Requirements versus Knowledge in the Quality Management of the Global Engineering Process within an Organization in the Aerospace Industry

Abstract

This paper presents original research on the identification and modeling of quality requirements for structural products in aircraft structures. As the main objective of this research, the authors focused on identifying the relationship between the previously mentioned requirements and the technical knowledge necessary to improve the quality of the processes involved. This scientific paper presents research in terms of defining a global engineering process addressing, as a starting point, the requirements necessary to be met in the manufacture of structural products for the structure of aircraft. The authors have identified directions for improvement in the global engineering process which will certainly lead to the creation of a sustainable, competitive advantage for the organization where the research was conducted. Based on the concept of intellectual capital and its components, the authors developed a model of knowledge analysis related to the requirements in order to later develop knowledge matrices at the subprocess level. This research presents a pragmatic evaluation based on the experience of those involved, but also on a study focused on pre-modeling the knowledge necessary to be considered and involved in the global engineering process. After this desideratum, the relationship between knowledge–requirements, but also the relationship between requirements–knowledge, was achieved, establishing a direct connection with the global quality of the analyzed products from the perspective of streamlining the global engineering process. This research is based on an entire procedure of analysis and modeling of the processes and subprocesses considered that could lead to favorable results from an economic point of view, but also from a technical point of view, the recommendation being to implement those presented to increase the competitive advantage in the profiled market.

1. Introduction

Correlating product quality requirements with awareness in the global process is an original approach to quality management in an aerospace organization so that compliance with product requirements can lead to the efficiency of the aforementioned process and also to the effectiveness of the relationship between requirements and knowledge [1,2,3,4].

Figure 1 shows the approach of the relationship between product requirements in the context of the global engineering process, generated by the need to improve process quality in the organization where the research was conducted by reducing the costs of implementing new structural products. Regarding the structural products, reference works are mentioned [5,6,7,8,9,10,11,12].

Following the financial analysis of the organization, in terms of production costs, two areas of improvement were identified related to engineering processes, namely reducing the number of nonconformities, and reducing the time of evaluation and interpretation of product quality requirements. The first direction, namely the reduction of nonconformities, is a direction that is supported by methods of the quality management system such as analysis of nonconformities, corrective actions, and continuous improvement; on the other hand, the second direction is not supported by such methods but rather depends on the way in which the management of knowledge and product quality requirements is carried out.

The specialized bibliography approaches knowledge management from a theoretical point of view and refers to the field of activity of the organization without going into the details within it. In this sense, the authors mentioned [13,14,15] produced work that deals with such matters.

This paper presents, in a detailed way, the place and role of the global engineering process but also all the technical and managerial aspects related to this subject, with an application within an industrial organization in the aerospace field.

This study originated from the need for quality improvements in an aerospace manufacturing organization which had to manage a large amount of product requirements during a transfer of work and industrialization process.

In the specific domain literature, there could not be identified a similar approach on the direct relationship between knowledge and product quality requirements. These subjects bring in the discussion from a general perspective.

The research can be considered as starting with the approach method on a product quality requirement breakdown and a direct connection to the engineering process deliverables. This approach provides a baseline for the engineering knowledge gap analysis for any industrial organization which intends to industrialize new products, as well as a starting point to develop the training plans to cover new requirements.

The main goal of this research is to provide a method, together with first versions of different analysis tools, that any engineering organization can use to scan its level of knowledge in relation to the products realized. In addition to applying these methods and tools, this study validates the method, at least in the research condition. Finally, this research opens new research directions.

The current manuscript is structured as follows. In Section 2, the theoretical framework is presented. In Section 3, the research methodology is described. In Section 4, the authors present the knowledge analysis in an aerospace industrial organization, and in Section 5 is presented the assessment of knowledge involved in the global engineering process and its relationship with product quality requirements. Finally, to conclude the paper, the principal conclusions of the study are made known, followed by the study limitations and future research.

2. Theoretical Framework

Developed countries are emerging economies, and they produce a lot of thanks to technological innovations, especially in the current era (i.e., in the era of Industrial Revolution 4.0, which means that all economic activities must develop technological innovations to increase the productivity of all activities) from economics [16]. The concept of open innovation and its sub-attribute of ecological innovation should be viewed through the lens of corporate governance and how managers make decisions about the application of research, development, and innovation [17].

Open innovation can lead to the elimination of shortcomings arising from inadequate knowledge [18,19]. Experience is a particularly important parameter of open innovation, as the relevant literature demonstrates. In fact, in experience-based companies, where innovation processes are based on technical knowledge, there is a positive correlation between the level of openness and the effectiveness of innovation [20].

The need for open innovation becomes more apparent when companies must address issues of environmental compliance, the need for modern technologies, the needs of customers, the need for effective communication with external stakeholders, and the need for new knowledge [21]. One of the main reasons companies adopt open innovation is that they find it hard to afford to innovate on their own [22].

Article [23] states that open innovation in companies through sustainable development includes business development, co-creation, knowledge management, mitigation of climate change and environmental impacts, ecosystems, decision-making, the economy, the cycle of life, and energy efficiency, which in turn are promising topics for future research and the achievement of industry goals. In an article [24] on the dynamics of open innovation, the authors identified a consumer behavior decision-making process that will help marketing managers create a marketing strategy that will make the consumer want to buy. In [25], the authors emphasize the fact that economic development measures that affect only the leading industries may have no other effect than the impact on the acceleration of economic growth. It is mentioned in [26] that the development of a dynamic culture of open innovation is important to achieve truly open innovation in public organizations, because in addition to legal and institutional barriers, cultural barriers must be overcome. If open innovation is implemented effectively, its momentum can lead to significant company growth [27].

According to the theory of open innovation [28], a holistic cognitive approach should allow a company to effectively explore internal knowledge and assimilate external knowledge about a dynamic environment [29,30,31]. On the other hand, innovation has been defined as a tool that “combines existing knowledge in new ways” [32,33], highlighting the limits and potential of the organization’s cognitive substratum to promote sustainability and innovation.

Until recently, knowledge was primarily perceived as something positive that organizations must deal with to get the most out of it. The development of the field of knowledge management has evolved into practices, processes, activities and other potential knowledge management tools and measures to support organizations in achieving this goal. So, organizations have focused on finding and developing the right knowledge and using it to their advantage.

Economics, organization, and management based on knowledge are commonly used concepts when we talk about new economic trends. This fact is mainly related to the knowledge revolution of the 21st century, which drew attention to knowledge, considered as the main element in ensuring the functionality and efficiency of organizations.

The availability of information and knowledge management guide corporate innovation processes towards greater competitive advantage.

Process management is recognized as a set of methods and techniques for discovering a business process, developing designs for this process, monitoring it through data measurement, and optimizing and automating the process using human, technological, and financial resources [34].

The entire process management life cycle requires innovation at every step to accelerate workflows [35]. Such innovations must also be closely aligned with organizational goals, namely exploration and exploitation, to meet the needs of ambidexterity in the digital knowledge economy. Knowledge-sharing among process teams, from the most experienced to the newcomers, is critical to the success of process management [36]. Article [37] also identified four project-based factors, including (1) task specialization, (2) knowledge transfer, (3) knowledge transformation, and (4) uncertainty and change management, which help to embrace ambidexterity.

Previous research has shown that some of the core elements of process management (e.g., strategic alignment, people, culture, and governance) play a vital role in the successful implementation of a business process [38]. For example, the organizational structure should support the organization’s adoption of process control at different hierarchical levels (e.g., board of directors, managers, and assembly-line workers) [39]. Similarly, an organization’s external environment (e.g., stakeholders, customers, and competitors) can influence the performance of process management when a new technology enters the market. Consequently, [40] summarized these contextual factors into four groups, namely goal-related, process-related, organizational factors, and environmental process management context factors. Repetition is also seen in studies of process management maturity models and their recommendations for achieving wider adoption of process management [41].

One of the most important aspects to consider is the current tendency of companies to focus on intensive knowledge and the capitalization of new ideas that lead to innovation. At the current stage of economic life, businesses can be built more on models of thinking than on models of their products and services offered. For an organization to be effective, it is equally important that the problem be questioned in terms of the effective distribution of products as well as the transformation of intangible assets in economic value. Finally, when products and services are postponed, competition in the market is measured from the point of view of intangible assets.

Intellectual capital becomes the main factor in the management of production and reproduction processes in the economic system. Of all the factors of production, the greatest added value was brought by the knowledge that was created. This knowledge, in the economic interpretation of a key factor, allows for the generation of benefits over a lengthy period, guaranteeing the competitive advantage of the company, and forms the basis of intellectual capital. This knowledge, combined with the potential of human skills, competencies, ideas, intuition, professional experience, working methods, and customer relations, is called intellectual capital [42,43].

Knowledge-based thinking provides a systematic and engaging direction for creative problem solving by integrating human, business, and technical factors with a focus on creating innovative solutions based on a user-centric perspective. An increasing number of companies and institutions is adopting this method of user-centric innovation, along with mindsets and toolkits [43,44].

3. Research Methodology

The research methodology used is a qualitative one, since the main objective of this research is to identify the factors which have the most impact on the relationship between knowledge, product requirements, and product quality. This research is based on case studies in an organization where the author faces engineering challenges with product requirements in daily activities. The study was planned in a longitudinal time horizon considering the distinct types of products that have been implemented in the manufacturing process. In addition, the data related to the products’ quality impacted by the engineering deliverables could be collected due to the traceability process implemented in the organizational study. Also, for every deliverable produced and for every product, information was collected from each engineering process, such as product number and revision, employee name, and creation and release dates. Knowing the name of the employee who realized the deliverables, periodic evaluation results for them, and results of nonconformity analysis, the matrix method was used to identify any areas where gaps of knowledge exist.

Figure 2 presents the scheme of research design which describes the processes and techniques for data collection and data analysis.

This paper’s objective is to highlight the importance of knowledge-level in the engineering process and the impact it has on the quality of manufactured products. All this is possible because the main manufacturing process input, next to materials, is engineering deliverables. Every misinterpreted product requirement is implemented in the manufacturing process, i.e., on products considered as requirements. Even if there is a quality control process in place, there are nonconform products realized that generate unnecessary cost.

4. Knowledge Analysis in an Aerospace Industrial Organization

The approach to intellectual capital within some industrial organizations is an extremely complex subject, and most studies in this field mention the need to establish the particularities of the study in making a relevant analysis of intellectual capital. The approach of intellectual capital in the context of research is focused on the analysis of this desideratum used in the global engineering process within an industrial organization in the field of aerospace. Without considering the concept of global intellectual capital and process management by correctly identifying which knowledge is needed, a pertinent analysis of the global engineering process and the mapping of this global process proposed in the research is not possible [45,46]. The aim was to follow a path of information in a global context and, at the same time, analyze each stage as a component part of the previously mentioned process.

The global engineering process we are referring to can be integrated into a quality management system that can bring about improvement in all requirements in the context in which we propose the application of continuous improvement.

The process we are referring to, being a functional process in a real industrial organization, is integrated in a quality management system, it being a “frozen” process, i.e., a process that can only be modified through a process of improvement according to the requirements of the quality management system. In the study we present, we considered that any process can be continuously improved by improving the capital of the intellect used in the process.

The engineering processes within industrial organizations in the analyzed industry have, as a mechanism, intellectual capital oriented towards the technical and managerial fields. Complementary to these areas, knowledge of the processes within the quality management system and communication knowledge were paramount due to the impact they can have on the development of processes.

It has been established what knowledge is to be evaluated in the global engineering process, and we propose an analysis model aimed at identifying all the knowledge that is involved in transforming product quality requirements.

The large volume of information generated by the multitude of activities throughout the process, being quite difficult to manage, motivated us, at this point in the research, to approach it in a structured and logical way.

The global engineering process consists of eight main processes, structured in three groups. These groups have been designed based on the types of deliverables that these processes generate. Figure 3 shows how these processes were distributed.

As shown in Figure 4, each process consists of subprocesses, which are performed by a sequence of activities. Identification of the knowledge used in these activities was achieved by asking three basic questions for each activity, namely:

-

How is the activity done?

-

Who performs the activity?

-

How is the deliverable confirmed, or how is the activity completed?

The model presented in Figure 4 is limited to the actual study context, considering a management perspective over the process. The grouping of the process is based on this specific study in one manufacturing organization. Of course, this can be adapted to any manufacturing organization based on its processes structure.

For a better understanding of the approach, presented below are the expectations of what is to be achieved after completing the questionnaire for the process.

The first question regarding how the activity is performed leads to obtaining the details of the activity from the point of view of the execution process of the activity, namely, a human-resource thinking activity or an activity of simulation and calculation of an application or equipment.

The second question regarding who performs the activity is complementary to the first question and obtains specific information on the type of resource that is involved in the execution of the activity.

The last question regarding how the deliverable is confirmed, or the completion of the activity, aims to identify how to control the activity, the type of resource needed to complete the deliverables, and the completion of the respective activities and processes.

The studied process, being an engineering process, is mainly oriented towards the use of human resources, i.e., the technical knowledge specific to the industrial field. The issue of human resources has been addressed in works such as [47,48].

Following the application of the analysis model of the global engineering process, the knowledge necessary to carry out the activities within the engineering process can be identified according to Figure 5.

The four types of knowledge were considered because of how engineering activities can be executed. If any engineering activity is to be realized, the person who executes it must have technical knowledge to understand the product requirements as well as the organization’s capabilities. To transform the requirements into the deliverable required in the manufacturing process, software skills become necessary. Without knowing how the internal quality management systems work, knowing which procedure and traceability process is required to be followed in order to realize the deliverables can be considered nonconforming output to internal processes. All this knowledge is used to prepare the deliverable required for an organization; in addition, communication knowledge is required to assure that internal project planning is respected, and that any other organizational employee receives the correct and complete product requirements.

Technical knowledge (k_t), in the industrial organization approached, is represented by knowledge of basic mechanical engineering and general knowledge of engineering.

In an organization with the field of activity aimed at the manufacture of structural components of aircraft, mechanical engineering knowledge is considered basic knowledge. The vast field of technical knowledge has been reduced to the manufacture of metal structural components in the aerospace field. Manufacturing issues are addressed in different research by [47,48,49,50,51]. According to Figure 6, in addition to the basic technical knowledge of mechanical engineering, for the realization of metal structural components, specific knowledge in the field of aerospace is also required. Some of this is complementary to general knowledge, bringing only the specificity of the field, such as:

• Technical design, tolerances, and dimensional control—which bring particularities to the aerospace field;
• Study of materials—which only complements the basic knowledge with that on specific materials used in this field;
• Basic knowledge of technological manufacturing processes—which is also supplemented with knowledge of aerospace-specific technological processes, which is distributed in this field through so-called process specifications.

All this technical knowledge is used and developed in organizations through engineering processes, which is why this scientific paper is aimed at this area. Aspects regarding technical documentation are approached in different research by [52,53,54].

Knowledge of internal processes within the QMS (k_p) manages activities in accordance with internal procedures and instructions. This is especially important because it concerns the management of product quality requirements from the point of view of the quality management system, as well as certain product quality requirements integrated into these procedures. Therefore, the proper conduct of processes and activities of organizations depends on compliance with these procedures. However, without this knowledge, the risk of making non-compliant products is higher. Ensuring knowledge at the level of all resources is achieved through:

• Regular training of resources followed by evaluations;
• Implementation of automation in applications used in organizational processes;
• Periodic auditing of processes, both internal and external.

Within all internal organizations, the quality management system provides, according to the standard AS9100D [55], guidance related to how the knowledge shall be gained and from which resources. Thus, the research in this study is intended to be a complement to these requirements with the aim of improving the approach to internal processes from the perspective of the necessary knowledge.

Software knowledge (k_s) is needed to use and develop IT solutions to support the activities of the global engineering process. Nowadays, IT applications have taken over a large part of certain engineering activities, especially those of design, programming of numerically controlled mechanical processing machines, programming of measuring equipment, heat-treatment equipment, plastic deformation, automatic painting lines, etc. Aspects regarding the global engineering process in this context have also been identified in the literature, in works such as [56,57,58].

The software knowledge used in the global engineering process within industrial organizations in the field of aerospace is directly correlated with the IT applications used in this process. In this context, it is about:

• Knowledge of using PLM applications (Product Lifecycle Management), WEB (web platforms of PLM applications), and MS OFFICE (general communication applications and general information management);
• Knowledge of using ERP applications (Enterprise Resource Planning);
• Knowledge of using CAD applications (Computer Aided Design);
• Knowledge of using CAM applications (Computer Aided Manufacturing);
• Knowledge of using CMM applications (Coordinate Measuring Machine).

Similar aspects are presented regarding the aerospace field by [59,60,61].

For a better understanding of how to use applications in the global engineering process, Figure 7 presents the types of applications used in each individual process, as well as some examples of these applications.

The level of knowledge regarding the use of these applications has a direct impact on the productivity and efficiency of activities within the processes. The higher the level, the shorter the time required for the activity, resulting in higher productivity. At the same time, a higher level of application knowledge builds on the ability of resources. In this way, the efficiency of the activity is ensured through the control and execution of the activity in relation to its entrances and exits.

Through communication knowledge (k_c), resources communicate within an organization and externally in relation to product quality requirements. In the analyzed bibliographical references, the subject is approached by [62]. This knowledge is important in this study because it is an important part of intellectual capital. At the same time, any activity within the engineering process that is performed by human resources also needs communication skills to streamline the entire process. Therefore, good communication regarding product quality requirements ensures a good transfer of information, i.e., a better interpretation of it.

The communication of information related to communication knowledge connected to product quality requirements refers to operational communication consisting of the messages within the organization that are transmitted for the realization of the operational plan.

Figure 8 represents graphically the area where communication applied in the global engineering process is found in relation to organizational communication.

This communication, as mentioned above, is related to the requirements of the products within the process, but also outside it, in the context of operational communication.

The importance of this type of communication is evidenced by the impact it has on product quality requirements throughout the management process, from receiving the requirements from the customer, to interpreting them, to carrying out the manufacturing process, to controlling the requirements and certifying products in relation to customer requirements.

The communication skills used in the global engineering process in aerospace industry organizations are:

• Knowledge of the official language of the field used in the transmission of product requirements, namely, English;
• Knowledge of the formulation of internal requirements always using references to documented and authorized information;
• Knowledge of the level of detail that must be contained in a message, depending on the recipient of the message.

An example is presented of communication to senior management regarding the stage of implementation of some products for which an implementation delay is due to interpretation of the requirements regarding the achievement of the mechanical properties of the materials and the way in which they are verified. This communication is not appropriate since the message does not transmit information about the stage and also includes certain details that are not required. This example can have an impact on product quality requirements for on-time delivery through the ability of the message to generate product de-planning because of the lack of information on the real stage of the product implementation process within the organization.

Communication skills are a difficult topic for industry organizations to address because they are acquired with professional experience. Therefore, organizations that are at the beginning of the road most often encounter this lack of knowledge [63,64,65,66]. Of course, in addition to these types of communication skills, there are many others that have an impact on the organization but are not the subject of this study.

In this phase, we established the types of knowledge generally used in the global engineering process. Next, we analyzed the activities that generate the process deliverables with the greatest impact on the whole process and on the product quality requirements.

The proposed model for the analysis, evaluation, and relation of the knowledge involved in the global engineering process, aims to:

• Identify the distribution of types of knowledge in the process;
• Highlight that knowledge with the greatest impact on the process;
• Highlight that knowledge with the greatest impact on the quality requirements of the products managed by the process.

The structuring of the information and its coding have the role of facilitating identification of those activities and deliverables that are of interest from the total activities that are carried out within the organization. The code of each activity is performed according to Figure 9.

Table 1. Description of the activities of process groups G1.1 and G1.2.

Process Code/ Process Description	Subprocess Code/ Subprocess Description	Deliverable Code/ Deliverable Description	Activity Code/ Activity Description
G1.1 Receipt and analysis of documentation	G1.1.1 Receipt and registration of documentation	G1.1.1.L1 Technical product documentation registered in PLM	G1.1.1.A1 Accessing the technical documentation of the product in the customer’s system
			G1.1.1.A2 Downloading files and saving them to the right location on your internal network
			G1.1.1.A3 Registration of technical documentation in the internal PLM application and sorting of documents in terms of document type
			G1.1.1.A4 Communication of confirmation of registration of technical documents in the PLM system
	G1.1.2 Analysis of technical documentation	G1.1.2.L1 Technical information on technical documents	G1.1.2.A1 Identification of technical documentation applicable to each part
		G1.1.2.L2 Number of internal articles in the PLM application accompanied by structured product technical documentation.	G1.1.2.A2 Collection of information on technical product documentation (drawing number, revision, drawings, material lists, supplementary documents, 3D model, etc.)
			G1.1.2.A3 Sorting and validating all technical documents applicable to each individual product
	G1.1.3 Achieving product manufacturing feasibility	G1.1.3.L1 Feasibility report	G1.1.3.A1 Establishing technical teams to analyze the feasibility of product manufacturing
			G1.1.3.A2 Revision of the technical documentation of the products to identify the manufacturing and inspection processes
			G1.1.3.A3 Review of manufacturing and inspection process requirements
			G1.1.3.A4 Review of product capability in terms of technological equipment capability
			G1.1.3.A5 Identifying the certification requirements of the identified processes and the purchase of manufacturing / inspection equipment or confirming their availability
			G1.1.3.A6 Validation of the feasibility report
G1.2 Definition in the ERP system	G1.2.1 Defining items (products) in the ERP system	G1.2.1.L1 Internal article defined in the internal ERP system	G1.2.1.A1 Establishing the internal article code
			G1.2.1.A2 Entering specific article details
			G1.2.1.A3 Verification and validation of article data
	G1.2.2 Transfer of technical data to the ERP system database	G1.2.2.L1 Technical information per item corresponding to product quality requirements	G1.2.2.A1 Introduction of the technical details of the products regarding the applicable technical documentation
		G1.2.2.L2 Information on the material required according to the product quality requirements	G1.2.2.A2 Introduction of technical details on the materials needed to make the products
			G1.2.2.A3 Introduction of technical product details on special product requirements
	G1.2.3 Attachment to technical documentation in ERP	G1.2.3.L1 Technical product documentation attached to each item in the ERP system	G1.2.3.A1 Identification of documentation applicable to each product in accordance with the requirements of the ERP system
			G1.2.3.A2 Attaching the technical documentation corresponding to each article and revision

,

Table 2. Description of the activities of process groups G1.3 and G2.4.

Process Code/ Process Description	Subprocess Code/ Subprocess Description	Deliverable Code/ Deliverable Description	Activity Code/ Activity Description
G1.3 The process of preparing the supporting documentation for the manufacturing process	G1.3.1 Preparation of 3D Models	G1.3.1.L1 3D model that incorporates all the geometric requirements of the product to be made.	G1.3.1.A1 Establishing the applicable technical documents
			G1.3.1.A2 Verification of the 3D model received from the customer in relation to the condition of delivery of the product
			G1.3.1.A3 Updating/creating 3D model using 2D drawing and complementary requirements (delivery condition, internal 3D modeling standards)
			G1.3.1.A4 Verification and approval of the 3D model made
	G1.3.2 Preparation of support drawings for manufacturing	G1.3.2.L1 Internal design that incorporates the quality requirements of the products complementary to the 2D customer drawings and the internal sizing requirements	G1.3.2.A1 Realization of the internal design of execution using the previously approved 3D model (addition of necessary internal requirements in the manufacturing and inspection processes)
			G1.3.2.A2 Verification and approval of the 2D drawing made
	G1.3.3 Preparation of the support drawings for the painting process	G1.3.3.L1 Internal drawing with instructions for painting product surfaces	G1.3.3.A1 Conducting the internal drawing-painting instruction using the previously approved 3D model (adding the necessary internal requirements in the manufacturing and inspection processes
			G1.3.3.A2 Verification and approval of the 2D drawing made
G2.4 Implementation of the semi-finished product transformation strategy	G2.4.1 Defining the material requirement for product processing	G2.4.1.L1 Semi-finished product information: technical specifications and dimensions	G2.4.1.A1 Analysis and interpretation of the technical execution documentation
			G2.4.1.A2 Analysis and interpretation of material specifications
			G2.4.1.A3 Machine tool capability analysis
			G2.4.1.A4 Realization of the technological concept of execution for mechanical operations
			G2.4.1.A5 Defining the dimensions of the semi-finished product including the technological additions
	G2.4.2 Establishment of the technological itinerary regarding the mechanical operations (Deformation, Heat Treatments, and Machining)	G2.4.2.L1 Technological itinerary of the mechanical and thermal processes applicable to the product	G2.4.2.A1 Analysis of the requirements regarding the manufacturing process from the technical documentation of the product
			G2.4.2.A2 Analysis and validation of the concept of technological flow regarding mechanical operations

,

Table 3. Description of process group activities G2.5 and G2.6.

Process Code/ Process Description	Subprocess Code/ Subprocess Description	Deliverable Code/ Deliverable Description	Activity Code/ Activity Description
G2.5 Realization of the numerical control program for CNC	G.2.5.1 Realization of the CAM program and the concept of CNC clamping devices	G2.5.1.L1 NC program	G.2.5.1.A1 Establishing the processing strategy (3, 4, or 5 axes)
			G.2.5.1.A2 Setting the machine tool
		G2.5.1.L2 Device technological concept	G.2.5.1.A3 Defining a technological concept for holding the semi-finished product
			G.2.5.1.A5 Generating the NC program and simulating the NC program in Vericut (in terms of collisions and process parameters)
	G.2.5.2 Realization of the execution support documentation and attachment in the ERP system	G2.5.2.L1 Mechanical operations execution file	G.2.5.2.A1 Drawing up instructions for preparing the machine tool and attaching the semi-finished products to the device
		G2.5.2.L2 NC program reference in the ERP system	G.2.5.2.A2 Attaching the technical execution documentation (NC Program, Toolkit List, and Execution File) to the corresponding ERP system of the product item
G2.6 Designing and making devices	G2.6.1 Device design	G2.6.1.L1 Device design documentation	G2.6.1.A1 Realization of the device concept using the technological concept
			G2.6.1.A2 Realization of the detailed 3D model of the device
			G2.6.1.A3 Verification and validation with the CAM program in terms of operation
	G2.6.2 Preparation of execution documentation	G2.6.2.L1 Installation, disassembly instructions	G.2.6.2.A1 Drawing up the overall 2D drawings and the list of components
			G.2.6.2.A2 Drawing up the execution drawings of the parts and the necessary semi-finished products
			G.2.6.2.A3 Verification and approval of the device execution documentation
			G.2.6.2.A4 Attaching the device documentation in the ERP system to the appropriate items.
	G2.6.3 Manufacture of devices	G2.6.3.L1 Device to be used in production	G.2.6.3.A1 Launching the components of the device
			G.2.6.3.A2 Placing purchase orders for components that cannot be done internally
			G.2.6.3.A3 Device assembly
			G.2.6.3.A4 Device verification and certification

and

Table 4. Description of the activities of process groups G3.7 and G3.8.

Process Code/ Process Description	Subprocess Code/ Subprocess Description	Deliverable Code/ Deliverable Description	Activity Code/ Activity Description
G3.7 Establishing the technological route	G3.7.1 Defining the technological route for individual products	G3.7.1.L1 Technological route—mechanical operations, surface treatment, inspection, and logistics	G3.7.1.A1 Analysis of the technical documentation from the point of view of the processes applicable for the realization of the products
			G3.7.1.A2 Establishing operations and work sequences for manufacturing, inspection, and logistics processes
			G3.7.1.A3 Establishing specific work instructions for each operation and applicable customer process
		G3.7.1.L2 Manufacturing method defined in the ERP system—Electronic technology sheet	G3.7.1.A4 Validation of the technological itinerary
			G3.7.1.A5 Transfer of the technological itinerary in the ERP system
	G3.7.2 Defining the technological route for assembly operations	G3.7.2.L1 Complete technological route produced as a whole	G3.7.2.A1 Analysis of the technical documentation from the point of view of the applicable processes for the realization of the assembled products
			G3.7.2.A2 Establishing operations and work sequences for manufacturing, inspection, and logistics processes
		G3.7.2.L2 Manufacturing method defined in the ERP system—Electronic technology sheet	G3.7.2.A3 Establishing specific work instructions for each operation and applicable customer process
			G3.7.2.A4 Validation of the technological itinerary
			G3.7.2.A5 Transfer of the technological itinerary in the ERP system
G3.8 Implementation of inspection plans	G3.8.1 Preparation of the inspection plan	G3.8.1.L1 Inspection plan	G3.8.1.A1 Analysis of the technical documentation of product execution from the point of view of inspection requirements
			G3.8.1.A2 Identifying and extracting product quality requirements in the inspection plan
			G3.8.1.A3 Establishing inspection criteria for each characteristic
		G3.8.1.L2 Program for the coordinate measuring machine	G3.8.1.A4 Conducting the coordinate measurement program
			G3.8.1.A5 Verification and approval of the inspection plan
			G3.8.1.A6 Attaching the inspection plan to the ERP system

show the activities of the subprocesses involved in the global engineering process, as they are carried out in an industrial organization in the field of aerospace. Among the bibliographical references in which the subject of process modeling is touched, this work is mentioned [67,68,69,70].

For each activity, the types of knowledge necessary to carry it out were identified. A code has been assigned to each category of knowledge, which will be used later in the mathematical model of the global engineering process.

Following the analysis of the data presented (Table 1, Table 2, Table 3 and Table 4), it was found that the overall engineering process consists of a considerable number of corresponding subprocesses and activities (

Table 5. The content of the global engineering process in terms of the number of processes, subprocesses, activities, and deliverables.

Processes Group	Processes	Sub Processes	Activities	Deliverables
3	8	19	70	23

).

Identification of the types of knowledge was accomplished through analysis of the procedures and work instructions within the global engineering process. The functioning of the global engineering process in industrial organizations with a field of activity in the processing of structural components in the aerospace field is based on the knowledge of the resources involved in this process. The level of knowledge available regarding the process at a given time has a direct impact on the products, which are the result of the implementation of the knowledge-based thinking process.

Thirty-six categories of technical knowledge used in the global engineering process were identified. This technical knowledge is grouped into three different categories:

• General technical knowledge of the manufacture of metal products;
• Technical knowledge of aerospace structural products;
• Technical knowledge of aerospace-specific manufacturing processes.

The general technical knowledge of the manufacture of metal products involves the aspects presented in

Table 6. List of general technical knowledge required for the global engineering process.

Knowledge Category Code	Description of General Technical Knowledge
$K_{TG1}$	– Knowledge of aerospace product identification.
$K_{TG2}$	– Knowledge of identifying technical documentation designed for aerospace products.
$K_{TG3}$	– Knowledge of the stages of approval of the designed technical documentation.
$K_{TG4}$	– Knowledge of tree product organization.
$K_{TG5}$	– Knowledge of identifying types of technical documents specific to the aerospace field.
$K_{TG6}$	– Knowledge of the interpretation of technical drawings, 3D models, and symbols specific to the aerospace field.
$K_{TG7}$	– Knowledge of the interpretation of written requirements (texts) concerning the shape, deviations, tolerances, and characteristics of aerospace products.
$K_{TG8}$	– Knowledge of industrial technological equipment from the point of view of their capability (dimensions, accuracy, and technological capabilities).
$K_{TG9}$	– Knowledge of the general standards for making geometries in the 3D model (transitions from one plane to another using standard connection radii, criteria for development, bent, etc.).
$K_{TG10}$	– Technical knowledge of mechanical deformation operations in the field of aerospace.
$K_{TG11}$	– Technical knowledge of mechanical cutting operations in aerospace.
$K_{TG12}$	– Technical knowledge of aerospace heat-treatment operations.
$K_{TG13}$	– Technical knowledge of the preparation of machine tool and device preparation instructions.
$K_{TG14}$	– Technical knowledge of die design.
$K_{TG15}$	– Technical knowledge of the design of fasteners on the machine tool.
$K_{TG16}$	– Technical knowledge of the design of support devices for specific assembly operations.
$K_{TG17}$	– General technical knowledge on the execution of drawings.
$K_{TG18}$	– General technical knowledge of production organization.
$K_{TG19}$	– Technical knowledge of the operation from the point of view of the organizational system of the product manufacturing flow.
$K_{TG20}$	– General knowledge of locksmithing (reading 2D drawings and operating assembly equipment).
$K_{TG21}$	– General technical knowledge of device measurement and control methods.

.

The technical knowledge of structural products in the field of aerospace involves the aspects presented in

Table 7. List of technical knowledge of aerospace structural products.

Knowledge Category Code	Description of Technical Knowledge on Structural Products
$K_{TProduct1}$	– Knowledge of product type identification (technical specification, semi-finished product, part number, subassembly, assembly, standard element).
$K_{TProduct2}$	– Knowledge of grouping technical documents by article (product) by the customer.
$K_{TProduct3}$	– Knowledge of the extraction of structured information of the articles necessary in the manufacturing process.
$K_{TProduct4}$	– Technical knowledge of coding of technical documents and references of related documents.
$K_{TProdusct5}$	– Knowledge of the organization of articles in the internal systems of the organization (warehouses, projects).
$K_{TProduct6}$	– Technical knowledge of the use in the organization of the details of the technical documents of the products.
$K_{TProduct7}$	– Technical knowledge of materials used in aerospace.
$K_{TProduct8}$	– Knowledge of specific requirements for aerospace products (security classes and special inspections).
$K_{TProduct9}$	– Knowledge of 3D modeling of products in accordance with aerospace customer standards.
$K_{TProduct10}$	– Knowledge of the use of semi-finished products in the manufacture of the final product (observance of rolling and extrusion directions in the orientation of the final product).
$K_{TProduct11}$	– Knowledge of the interpretation of aerospace material specifications.

.

Technical knowledge on aerospace-specific manufacturing processes is presented in

Table 8. List of technical knowledge of aerospace-specific manufacturing processes.

Knowledge Category Code	Description of Technical Knowledge on Manufacturing Processes
$K_{TProcess1}$	– Knowledge of the identification of the manufacturing process of structural products in the aerospace field.
$K_{TProcess2}$	– Knowledge of the interpretation of aerospace-specific process specifications.
$K_{TProcess3}$	– Knowledge of the interpretation of process specifications specific to aerospace customers.
$K_{TProcess4}$	– Knowledge of the organization’s qualifications in aerospace manufacturing processes and their limitations.

.

Following the analysis of these issues, the knowledge regarding the internal processes within the quality management system was identified as being related to the component processes/subprocesses of the global engineering process.

This result is obvious, since the organization is certified from the point of view of the quality management system. In this context, the types of knowledge presented in

Table 9. List of QMS process knowledge.

Knowledge Category Code	Description of QMS Process Knowledge
$K_{P1}$	– Knowledge of internal document control procedures.
$K_{P2}$	– Knowledge of internal procedures regarding the confidentiality of aerospace technical data.
$K_{P3}$	– Knowledge of customer procedures for accessing technical documentation.
$K_{P4}$	– Knowledge of internal procedures for data security and confidentiality within the organization.
$K_{P5}$	– Knowledge of internal procedures for identifying the type of aerospace product.
$K_{P6}$	– Knowledge of internal file management procedures in the internal system.
$K_{P7}$	– Knowledge of internal registration procedures in the PLM application.
$K_{P8}$	– Knowledge of the internal procedures for managing the transfer of technical documentation from the client within the organization.
$K_{P9}$	– Knowledge of the flow of processes between the operational departments within the organization.
$K_{P10}$	– Knowledge of the procedures of the internal manufacturing and inspection processes.
$K_{P11}$	– Knowledge of specific internal procedures for recording technical data in the ERP application.
$K_{P12}$	– Knowledge of internal verification procedures and creation of internal 3D models corresponding to the products.
$K_{P13}$	– Knowledge of internal verification procedures and creation of 2D drawings in support of mechanical operations.
$K_{P14}$	– Knowledge of internal verification procedures and creation of 2D drawings in support of surface treatment operations.
$K_{P15}$	– Knowledge of the procedures of the internal processes for designing the processing strategy.
$K_{P16}$	– Knowledge of the procedures of the internal processes for defining the manufacturing route.
$K_{P17}$	– Knowledge of the procedures of the internal design processes of devices and molds.
$K_{P18}$	– Knowledge of internal process procedures for defining inspection criteria.
$K_{P19}$	– Knowledge of the procedures of the internal processes for carrying out assembly operations.
$K_{P20}$	– Knowledge of the procedures for the internal processes of programming coordinate-measuring equipment.

were identified.

Knowledge of IT applications plays an important role in the global engineering process since it provides the human resources involved in this process, the computing power, and the tools necessary for the design of manufacturing technologies and technical and commercial data management within organizations. In this context, the knowledge of various IT applications as presented in

Table 10. Software knowledge list.

Knowledge Category Code	Description of Software Knowledge
$K_{S1}$	– Knowledge of WEB applications and the use of an operating system.
$K_{S2}$	– Knowledge of secure file transfer applications.
$K_{S3}$	– Knowledge of using the PLM application.
$K_{S4}$	– Knowledge of using MS Office applications (Excel, Outlook, PowerPoint).
$K_{S5}$	– Knowledge of using the ERP application.
$K_{S6}$	– Knowledge of using CAD applications (especially Catia V5).
$K_{S7}$	– Knowledge of using CAM applications (Mastercam, Catia V5 CAM).
$K_{S8}$	– Knowledge of using the application of the definition of the technological itinerary.
$K_{S9}$	– Knowledge of using the CAMIO application.

was identified.

Communication skills are also the subject of this study. This knowledge is a factor in influencing product quality requirements because, in industrial organizations and especially in the global engineering process, the transmission of incorrect information regarding product quality requirements between the resources involved can directly alter the deliverables of component processes. Therefore, only three categories of knowledge presented in

Table 11. List of communication knowledge.

Knowledge Category Code	Description of Communication Skills
$K_{C1}$	– Knowledge of the communication of information in the official language of aerospace—English.
$K_{C2}$	– Knowledge of the communication of technical information relating to contract products.
$K_{C3}$	– Knowledge of the communication of technical information within organizations.

were identified.

Communication skills are found in all processes, subprocesses, and activities of the global engineering process. Through the analysis of the global engineering process, it was found that the industrial organization has developed its own language of communication, using very specific technical terms and references. Similar issues regarding industrial organizations are also addressed by [71,72].

For a better understanding of how knowledge is involved in the component activities of the global engineering process, the knowledge involved for each individual activity was identified following the study of this process. Thus, approaching each subprocess with the component activities, one can observe the variety of technical knowledge involved as well as the presence of each category of knowledge.

5. Assessment of Knowledge Involved in the Global Engineering Process and Its Relationship with Product Quality Requirements

Regardless of the field of activity, industrial organizations need a period during which they can gain the knowledge necessary to understand and interpret the requirements of product quality.

Figure 10 represents the author’s point of view about knowledge accumulation over time inside of an organization after multiple interactions with product requirements.

According to Figure 10, this time may vary depending on the level of basic knowledge and complexity, or, in other words, the level of product quality requirements.

This study raises the issue of identifying the possibility of improving knowledge within industrial organizations within a shorter period and with higher efficiency.

In Figure 10, point “A” is the point of intersection between the product quality requirements curve and the learning curve, at which point, at time interval “T”, the level of knowledge within the organization is equal (according) to the product quality requirements. Reducing the learning time ΔT to the interval T’ can be achieved only by optimizing the method of accumulating knowledge within organizations. Thus, the intersection point of the product quality requirements curve and the improved learning curve can be obtained at a shorter time interval, T’. From this, it can be deduced that the moment when the requirements are correlated with the knowledge of the organization is critical for reducing the type of assimilation. The efficiency of this relationship is directly related to the level of detail of the requirements and knowledge in the shortest possible time.

The quality requirements of aerospace structural products used in this study cover all common requirements for these types of products. Thus, starting from the four broad categories of structural product quality requirements, the use of level IV detailing was considered to correlate them with the knowledge involved in the global engineering process. Their coding was performed according to the coding scheme in Figure 11.

To be manufactured, the quality requirements of the products must contain at least the design requirements (shape, dimensions, and material tolerances). In addition, in the aerospace industry, they are also defined as:

• Aerospace-specific product quality requirements;
• Product manufacturing requirements in an organization with a certified quality management system;
• Legal requirements for passenger safety in the field of aerospace.

The purpose of the detail in Figure 11 is to define those requirements common to all metal structural products in the field of aerospace. This grouping has been done according to how these requirements are used to prepare deliverables in the global engineering process within industrial organizations in the field of aerospace.

The relationship between product quality requirements and the knowledge involved in this process is based on the following criteria:

• The requirement is used in the subprocess to achieve deliverability.
• The requirement is used in the activity to be evaluated and transferred to the next activity or subprocess.
• The requirement is used in the manufacturing process for the physical realization of the product.
• The requirement is used in quality-control processes.

After identifying the interaction between the quality requirements and the knowledge involved, it is much easier to assess the knowledge.

This knowledge consists of two components:

• Basic knowledge;
• Knowledge specific to the products being made.

Basic knowledge is acquired through learning in educational institutions. In this study, we limit ourselves to technical institutions—engineering. Thus, it is considered that most of the quality requirements of metal structural products in the aerospace field are covered by approximately 62% of the knowledge acquired through learning in the profile institutions. This assessment is based on a comparison of knowledge of aerospace-specific requirements with those generally applicable in the industrial field of metal products.

The distribution of the two types of knowledge within the requirements of the quality of structural products creates the possibility to verify the degree of influence of the knowledge on the requirements in the global engineering process when the deliverables are created. It also gives organizations the opportunity to analyze new product requirements in relation to the capabilities of the global engineering process.

Global engineering process capability represents the ability to transfer product quality requirements into process deliverables for the realization of products through manufacturing processes within the limits of all quality requirements received from customers. This capability is related to the knowledge available at some point in the process. Therefore, the more the knowledge in the processes covers the requirements of the product quality, the better the process capability.

Approaching the relationship between product quality requirements and the knowledge available within organizations either creates directions for improving knowledge or demonstrates the ability of the process to transfer the requirements communicated by customers in the manufacturing process to make the products (Figure 12).

In Figure 13, the split of basic knowledge was made by taking into consideration the technical requirement characteristics, such as the general knowledge learned in a technical high school or college. There is an approximation considered as a point of reference, which was reviewed in the study during the knowledge evaluation directly related to product requirements. Of course, the values can be considered only in the study case presented in this research. Still, there are a few research directions on this subject which were developed in future research.

This approach also greatly helps the process of analyzing product nonconformities, providing a direct channel from noncompliance with a requirement to the process or the processes that have had a direct influence on these requirements.

To be able to analyze the level of influence of the global engineering process on product manufacturing processes or, in other words, on product quality, the mathematical determination of the influence of knowledge on deliverables is the first step and will be the subject of further research.

6. Conclusions

As a theoretical contribution to this scientific work, the authors highlighted the relationship between knowledge and product quality, which is well-known, and all of us are trying to improve the quality by accumulating increased knowledge.

Still, a practical implication of the research shows one of the shortest paths in the improvement process—improvement of knowledge in relation to product requirements which are interacting within a noticeably brief time.

This paper represents an important part of the author’s doctoral thesis. Experience in the author’s structural parts manufacturing process organization supports a pragmatic view of how knowledge is managed to be developed to achieve high-quality products in today’s large, competitive aerospace industry market.

Another practical implication of the research addresses the relationship between product quality requirements and global engineering process knowledge through an ordinal approach to product requirement management from the perspective of engineering processes within aerospace industry organizations. In this context, directions for improvement related to engineering processes have been identified.

In this scientific paper, the efficiency of manufacturing processes has been practically approached from the perspective of engineering processes within organizations by achieving high-quality deliverables used in manufacturing processes.

Theoretically, the knowledge involved in the overall engineering process has been identified, for each individual activity, to practically create opportunities to evaluate and improve the process from different perspectives and is analyzed in this important study.

The entire study highlights the risk of misinterpreting the product requirements due to organizational knowledge being misaligned with them. The goal of this study was to make obvious that all requirements together must be understood and linked to organizational knowledge. The approach of the study, as explained in Figure 2, was to capture the logical research approach, guiding the researcher and filed engineers/managers whenever there were needs for improvements.

In the field of aerospace, due to the magnitude of both the volume and the complexity of the product requirements, the deliverables required for the manufacturing process require additional effort in terms of knowledge and methods by which they are made.

The identification of the deliverables of the manufacturing process was made by analyzing practically the quality management system and identifying the global engineering process.

Practically, the global engineering process of an industrial aerospace organization was detailed and analyzed using classical methods of analysis. Starting from the approach of intellectual capital, a model of knowledge analysis in the industrial organization was developed, the diversity of knowledge at the level of the organization’s processes was analyzed, and the knowledge matrices at the level of subprocesses were drawn up.

Three large groups of processes were identified, each consisting of eight processes. All eight processes consist of 19 subprocesses and 70 activities each. All this together generates a total of 23 deliverables needed for manufacturing processes, and more. In this context, the challenge was to determine which deliverables can streamline manufacturing processes the fastest and at the lowest cost.

To this end, a tool has been practically developed to analyze the influence of quality requirements on the deliverables required for manufacturing processes when making products.

The analysis of the interdependencies of deliverables at the time of their realization in the global engineering process led to the practical identification of deliverables with the greatest influence on the quality of the final product. The deliverable with the greatest influence has been identified as the 3D model of the finished part. Once the deliverables of the global engineering process were identified, their relationship with product quality requirements favored localization of the interactions between the processes, subprocesses, and, respectively, the activities of the global engineering process, with the product quality requirements.

This analysis ultimately led to the identification of the types of knowledge required in the global engineering process directly related to product quality requirements.

One aspect worth considering was the assessment of the knowledge involved in the overall engineering process and its relationship with product quality requirements.

This assessment is the preamble to the analysis of the level of influence of the global engineering process on product manufacturing processes or, in other words, on product quality, which may lead to the mathematical determination of the influence of knowledge on deliverables to be made in subsequent research.

This paper is part of a case study on real manufacturing organizations which face real issues in managing product quality requirements and how these are converted into deliverables and respectively into physical products. The issue being generated thereby is the level of knowledge.

Therefore, the conclusions drawn after the completion of this scientific research highlight the fact that the subject is a topical one among organizations with activity in the aerospace industry and, at the same time, opens new fields of research that can bring competitive and strategic advantages to companies.