Opportunities for Cleaner Production (CP) Using Process Flow Analysis: Case Study of a Furniture Manufacturer in the City of Palhoça (SC, Brazil)

The present article was aimed at identifying opportunities for cleaner production (CP) from the process flow analysis of a furniture manufacturing company located in the municipality of Palhoça (SC, Brazil). The company was used as an exploratory case study with a qualitative approach. The criteria used for the flow analysis and for identifying the opportunities of CP were associated to the systems and technologies employed, as well as to the process analysis and to the project layout factors (stock location, movement). With this, 107.24 m2 of wasted areas were found in the production environment, of which 72.06 m2 included the floor area with material to be discarded (waste) and 66.93 m of flow lines with returns and crossings. The study identified that the total flow lines of the company represented a total of 775.58 m, with the possibility of being reduced by 29.45%. This reduction is a result of optimizing the physical space and reducing waste with material handling. Twenty-five opportunities of a CP associated to the process flow analysis (layout) were listed. The analyses also indicated that the association of CP to process flows as a preventive measure leads to a new connection between process optimization and environmental performance.


Introduction
The adaption of companies to new trends in society, as well as to new technologies, the optimization of processes in the physical factory space, combined with the adaption to socio-environmental issues and the continuous search for a cleaner production (CP) are contemporary needs that increase competition levels, attached with social and environmental responsibilities.
Environmental issues bring great challenges to companies. These issues put pressure on companies to take into account environmental impacts in their business plans, as these impacts may have an effect on costs (reduction of time, material, and energy) and increase customer demand [1]. Environmental (lack of resources), regulatory (policies and legislation), and market pressures promote production and consumption standards that have less environmental impact, bringing new business opportunities and innovation [2].
Besides managing resources and optimizing processes, under an environmental management perspective, companies must fulfil the needs of the new profile of customers and consumers (green consumers) of products and services, who seek economic, social, and environmental responsibility (reducing waste, pollutants, and costs) [3]. In addition, the priorities of the industry of the contemporary and/or reducing by-products by reusing materials, besides reducing costs by the decline in consumption of materials, energy, and water. Therefore, the combination of the principles of CP and layout of the facilities can be considered innovation in the workplace. Moreover, the integration of CP in layout projects drives and potentializes efforts for reducing environmental impacts.
This study was based on the literature presented, but mainly, on the methodology from United Nations Industrial Development Organization (UNIDO)/ United Nations Environment Programme (UNEP) for implementing a CP program [13], on the manuals of the Brazilian National Centre of Clean Technologies (CNTL) [19,20], on criteria for implementing CP established by Tseng, Ling, and Chiu in 2009 [28], and on the factors and methodologies of layout projects systematized by Olivério [26] and Muther [27]. This research contributed to the association of CP analyses and process flows in the existing layout of the case study and enabled the identification of the opportunities.

Methodological Approach
This work consisted of an exploratory study, using a qualitative approach, as the data presented sought to understand the meaning, interactions, and opportunities to improve systems and technologies [33]. The quantitative data were presented to enhance the meanings [33], being a case study which provided detailed, contextualized, and broad knowledge of a reality that was used to lead theoretical reflections to the exploration and development of theories [34][35][36].
The study was carried out in a micro-enterprise located in the municipality of Palhoça, in the metropolitan region of Florianópolis, in the Brazilian state of Santa Catarina (SC), close to the federal motorway BR-101, an important longitudinal axis for the country.
The study began with the preparation of a questionnaire and an integrated checklist, applied in the period between 13 and 27 April 2015, with the support of the Unit of Design Management (NGD) from the Federal University of Santa Catarina (UFSC).
The questionnaire and integrated checklist were based on the report for the implementation of a cleaner production (CP) (Manual 4 from CNTL) [19], as well as on the methodology developed by UNIDO/UNEP for the implementation of the CP program [13], on the attributes of the criterion Systems and Technologies for the implementation of CP, as pointed out by Tseng, Lin, and Chiu in 2009 [28], combined with the factors and methodologies of the layout project (checklist) [26,27].
The criteria used for analyzing and identifying the opportunities for CP are related to Systems and Technologies (process analysis, layout of facilities, location and stock control, and movement of people and material), based on studies, factors, and consolidated methodologies regarding the implementation of CP and industrial layout projects. The methodological approach of this study can be described by steps 1, 2, and 3 of the methodology for implementing CP [19], adapted for this case study ( Figure 1).
The resources responsible for the transformation process in a production system are called inputs, which include information, human resources, energy, supplies, and material. In turn, outputs are products or services resulting from the transformation process [37].
In the technical visit for diagnosing the process flows of the company in study, based on the methodology used in industrial layout projects [26,27], we obtained the qualitative input data (raw materials, products, production routes) and output data (products, waste, residue, by-products), as well as the areas, arrangement of machinery, equipment, and sectors, information regarding the relationship between the different activities, the flow of materials, people, and information for product handling, measurements of the physical space, and the location of residues and by-products in the layout. Table 1 presents the design requirements included in the questionnaire and checklist carried out.  Steps for identifying cleaner production (CP) + flow analysis adapted to the case study. Adapted from the Brazilian National Center of Clean Technologies (CNTL, in Portuguese) [19].
Two technical visits were made to the company in the study in the year of 2015 for the application of the questionnaire and the integrated checklist, aimed at observing and mapping production processes. The integrated checklist assisted in direct observations and annotations and in measurements and observations about the physical space. The production manager accompanied the work to describe the process.
In addition, methodological procedures were carried out, such as a photographic and metric survey of the architectural space and the physical arrangement of machines and equipment. The questionnaire was not applied for obtaining data on the mass or energy balance, as the company did not have this information available.
Following the application of the questionnaire and the integrated checklist (1), photographic surveys (2), mapping of the physical space (3), and a description of the data was also carried out (4), drawing the respective zoning (5) and sectorized floor plans (6), performing a study on the interactions between the areas, sectors, and flows (7), with the flow layout plan being drawn (8), followed by the creation of a flowchart of the respective processes (9) with symbols being drawn according to the American Society of Mechanical Engineers (ASME). Finally, analyses (10) and the creation of a list with CP opportunities integrated with the factors of the layout project (11) were carried out.
The methodology used led to a new link between the optimization of processes and environmental performance, being also a breakthrough in comparison to the literature, as it provided guidance for the process flow analysis of the physical space of industrial facilities (layout) and contributed to the identification of CP opportunities associated to process flows.

Materials
Type of raw materials, specifications, reception and type of stocking; waste, residue, by-products, dust particles in the air; control of raw materials and by-products, space occupied, location of suppliers.
Machinery and equipment Types, specifications, safety and maintenance, location and space occupied.

Building
Measurements of physical spaces, location of machinery, equipment, furniture and people.
Analysis and improvement of process flows Wait Location of stock of raw material, finished material and material being processed, waste, delays, waste and by-product stocks, stock control, space occupied

Movement
Measurements of the flow of material during processing, description of processes, need of inter-relationships between areas and sectors, waste, crossings and floor obstruction with materials, by-products, machinery or equipment * Differentiated positioning of the company's management for systems and technologies both in monitoring and releasing information and in positioning the roles of each employee in the production process. People's relationships with physical space and process flows were associated with the attributes of the systems and technologies criterion and constituted as a new link between CP and flows and the link between people, CP, and process flows in physical space.

Description of the Company Used as a Case Study
This research was carried out in a micro-enterprise (ME) in the furniture manufacturing and trade industry, focused on furniture for offices, with a serial and tailored production process. According to the Brazilian Micro and Small Business Support Service (SEBRAE) [38], a micro-enterprise (ME) is a small business with a revenue equal to or lower than R$360,000 (Brazilian reals), with up to 19 workers (Complementary Federal Law no. 123/2006).
It covers a land area of 1410 m 2 , in a densely occupied commercial and industrial area (347.56 inhabitants per km 2 ) [39]. In 2015, it produced 10 different furniture lines for offices: Furniture for call centers, workstations, platforms, reception, and furniture lines with drawers, shelves, desks and archives. In 2018, the same furniture lines were still present, although there were changes in the design, with updates of the materials used and the inclusion of customized furniture.
In 2015, in its organigram, the company employed, apart from its director, 17 staff members (3 female and 14 male), with one of them being a production engineer. No quantitative record of waste of the material used was registered, such as medium-density fiberboard (MDF) or medium-density particleboard (MDP), among others. In 2018, waste (considered as by-products in this work) collection was still carried out by the same specialized company, although still without any quantitative record of the waste produced or of the respective final destination.
It was observed that the materials purchased by the company as MDF/MDP, had the FSC Brazil (Brazilian Forest Stewardship Council) seal, which ensures the ecologically correct origin of the wood used, that is, compliance with forest management norms and environmental and labor laws. However, the finished products did not have a seal directed to the furniture sector, being unable to attest the ecologically correct purchase of raw materials and the level of environmental performance. They did not have the proper management of industrial waste, or internal awareness and training actions related to social and environmental issues.

Zoning of the Areas from the Existing Layout
The zoning of the production centres of the layout simplified the study on the physical spatial needs and on the location of the facilities, enabling us to determine the distances covered for the movement of material and people, as well as the inter-relationships of the production areas. Figure 2 shows the zoning plan areas used as production centres in the company's site with the existing layout (survey carried out in 2015), as well as the location of the entrance of supplies and customers and the exit of the finished products. The floor plan also determines the respective areas used for the administration/sales (56.79 m 2 ) processes, as well as for the support of workers (20.01 m 2 ), stock/storage area (273.66 m 2 ), production (283.36 m 2 ), packaging and dispatch (120.79 m 2 ), by-products (98.96 m 2 ), and circulation (445.90 m 2 ).
It can be observed that the storage facilities, as well as the production and circulation areas, occupy the greatest areas (in ascending order), with a total of 273.66 m 2 being used for stocking/storage area, with 100.00 m 2 of the floor area close to the access of supplies/material and to the production area being occupied with MDF/MDP. Figure 2 indicates that there are 10 different areas considered underused/wasted in this work (107.24 m 2 ), which could be used in the production area or for improvements of the physical space (rectangle with red, dashed line).
The production, stock, and by-product areas were fragmented around the layout, with the areas used for by-products (98.96 m 2 ) being divided in areas with materials for reuse (6a) and in areas for the materials classified as for disposal waste (6b), totaling 72.06 m 2 of the floor area being occupied with materials to be discarded (waste). Moreover, 15 production areas were assigned for stocking the processing material (56.09 m 2 ), with 12 areas obstructing the floor area (39.45 m 2 ), indicating the lack of planning and control in terms of the movement and location of the material in the layout. The reuse of the by-products and the management of material from the sales process until being dispatched to the customer show an opportunity for reorganizing the layout areas, reducing waste, and clearing the physical space in order to expand the production area.
needs and on the location of the facilities, enabling us to determine the distances covered for the movement of material and people, as well as the inter-relationships of the production areas. Figure 2 shows the zoning plan areas used as production centres in the company's site with the existing layout (survey carried out in 2015), as well as the location of the entrance of supplies and customers and the exit of the finished products. The floor plan also determines the respective areas used for the administration/sales (56.79 m 2 ) processes, as well as for the support of workers (20.01 m 2 ), stock/storage area (273.66 m 2 ), production (283.36 m 2 ), packaging and dispatch (120.79 m 2 ), byproducts (98.96 m 2 ), and circulation (445.90 m 2 ). It can be observed that the storage facilities, as well as the production and circulation areas, occupy the greatest areas (in ascending order), with a total of 273.66 m 2 being used for stocking/storage area, with 100.00 m 2 of the floor area close to the access of supplies/material and to the production area being occupied with MDF/MDP. Figure 2 indicates that there are 10 different areas considered underused/wasted in this work (107.24 m 2 ), which could be used in the production area or for improvements of the physical space (rectangle with red, dashed line).
The production, stock, and by-product areas were fragmented around the layout, with the areas used for by-products (98.96 m 2 ) being divided in areas with materials for reuse (6a) and in areas for the materials classified as for disposal waste (6b), totaling 72.06 m 2 of the floor area being occupied with materials to be discarded (waste). Moreover, 15 production areas were assigned for stocking the processing material (56.09 m 2 ), with 12 areas obstructing the floor area (39.45 m 2 ), indicating the lack of planning and control in terms of the movement and location of the material in the layout.
The reuse of the by-products and the management of material from the sales process until being dispatched to the customer show an opportunity for reorganizing the layout areas, reducing waste, and clearing the physical space in order to expand the production area.

Production Centres and Sectorization of the Existing Layout
The location of the production sectors, as well as of the machinery, equipment, and stock of the material in the production centres of each department enables the study of the role, activities, and inter-relationship between the sectors ( Figure 3). Figure 3 sets out the location of the production centres, the sectors, and machinery, as well as the type of stocks, of supplies, fire extinguishers with the respective spanning radius, and the ducts for the extraction of sawdust particles in the existing layout.
With this, a lack of separation can be noticed between the entrance for customers, the reception (sector 1), and the exit of delivery vehicles (sector 25). Moreover, the stock of MDF/MDP panels (sector 8), the waste container (K1) for the disposal of several materials (sector 28), and the container (K2) for the disposal of MDF waste (sector 29) are located near the entrance of supplies for an easier reception of the material and easier exit of by-products.
The administration/sales area consists of the reception area (sector 1), the meeting area (sector 2), management (sector 3), and office/production, planning, and control (PPC) (sector 4). The management sector was responsible for managing resources and for the administration of the material according to the demand of the sales sector and production needs. In turn, the PPC sector (sector 4) oversaw the planning and control of the factory production centres.
Nevertheless, the PPC sector was located far from the production centres, with the greatest distances being to the cutting sections (A1 and A2), 76.19 m (sector 15a) and 74.58 m (sector 15b), respectively. This distance was considered disadvantageous for the production control and monitoring. The fact that the PPC sector is located far from the production area may also have a negative influence on the flow of information and on the quality control of the process and the product.
traction of sawdust particles in the existing layout. h this, a lack of separation can be noticed between the entrance for customers, the re ), and the exit of delivery vehicles (sector 25). Moreover, the stock of MDF/MDP , the waste container (K1) for the disposal of several materials (sector 28), and the co he disposal of MDF waste (sector 29) are located near the entrance of supplies for an of the material and easier exit of by-products. administration/sales area consists of the reception area (sector 1), the meeting area gement (sector 3), and office/production, planning, and control (PPC) (sector 4 ent sector was responsible for managing resources and for the administration according to the demand of the sales sector and production needs. In turn, the PPC oversaw the planning and control of the factory production centres. ertheless, the PPC sector was located far from the production centres, with the g being to the cutting sections (A1 and A2), 76.19 m (sector 15a) and 74.58 m (secto ely. This distance was considered disadvantageous for the production contr ng. The fact that the PPC sector is located far from the production area may also influence on the flow of information and on the quality control of the process a  Figure 3 illustrates the location of eight storage areas, fragmented throughout the production area, as follows: Edging tape stock (sector 7), MDF stock (sector 8), stock of components for the assembly of drawers (sector 9), stock of assembled drawers (sector 10), stock of components for assembling cupboards and tables (sector 11), cardboard stock (sector 12), stock of finished material (sector 13), and storeroom (sector 14).
The cardboard stock (sector 12) was divided into five spaces shared with processing material, close to the assembly of cupboards (sectors 23a and 23b), being also located close to the packaging and dispatch sector (sector 24) and to the stock of finished material (sector 13) to facilitate the tasks. A certain amount of cardboard waste was observed in the space underneath the stairs, obstructing the area and compromising the organization.
The production area was divided into cutting sectors (sectors 15a, 15b, and 15c), CNC (Computer Numeric Control) machining center (sector 16), router (sector 17), automatic gluing of edge tape (sector 18), manual gluing of edge tape (sector 19), manual drilling of drawers (sectors 20a and 20b), assembly of drawers (sector 21), cupboard drilling (sector 22), and cupboard assembly (sectors 23a and 23b). The packaging and dispatch area (sector 24) was located at the end of the process, near the exit of finished material.
The absence of waste containers for the selective collection of by-products could be observed in the production sectors. In addition, the improper sealing of the area surrounding the collection and extraction of sawdust (sector 32) spread sawdust particles in the air during the extraction of sawdust from the silo, impregnating an area of 249.21 m 2 with particles (area affected marked in Figure 3 with a dashed-line rectangle in green).
Six MDF/MDP waste sectors (sector 26) were present, as well as five sectors of unused MDF/MDP (sector 27). The material was leaning on wooden planks, columns, walls, and machines, with two of them being mixed with the waste material next to the containers. Therefore, it can be argued that the company did not have a preventive view regarding CP ( Figure 3).
The location of the fire extinguishers in the layout (dashed-line circles in grey, in Figure 2) shows the respective spanning range (10.00 m, according to Brazilian Regulatory Standard NR-23) [40] and the risk areas, where the extinguishers did not reach, indicating the need of complying with the Fire Protection Standards (NR-23) and improving work safety.
The location of the respective sectors followed the sequence of the production flow, although some obstruction of the floor space could be observed in the production and circulation areas. The need for optimizing the spaces and flows was also observed and identified by eliminating returns and crossings to improve the movement of material and people throughout the process, as well as improvements in terms of cleaning procedures and in the organization of the production center. In addition, there is the need of adapting the transport, movement, storage, and handling of material to the current standards in place (according to Brazilian Regulatory Standard NR-11) [41], in order to avoid piling material within 0.50 cm from the structural elements of the building, avoiding the obstruction of firefighting equipment.

Process Flow and Supply in the Existing Layout
By mapping the flow lines and supply of the production process, it was possible to obtain information regarding the movement of material and human resources throughout the production chain, such as the number of movements and distances covered by the material and people, as well as flow crossings and returns. The objective of this mapping was to identify critical points to be optimized in the layout. Figure 4 shows the floor plan with the production, delivery, and customer flow lines, considering the production centres of each sector (Figure 3) in the existing layout.
The furniture manufacturing processes of the company were divided into tabletops, straight connections, and curves (A); cupboards, shelves, and partitions (B); and drawers (C). The furniture manufacturing started when all elements were concentrated in the cutting sector (15a, 15b, and 15c), with sectioning machines (A1 and A2) or a sliding table saw (B) (Figure 4).
The flow lines for the manufacturing of tabletops and straight and curved connections (production A) are represented in Figure 4 with continuous (red) lines, totaling 142.12 m. The cut furniture pieces could be transported to the automatic gluing of edge tape sector (sector 18) and/or to the manual gluing of edge tape sector (sector 19), or even to the router (sector 17) or to the machining sector (sector 16), then returned to the gluing of edge tape sector (sectors 18 and 19). The finished pieces were then transported to the stock of finished material (sector 13).  The flow lines for the production of cupboards, shelves, and partitions (production B), represented in Figure 4 with (red) dashed lines, covered a total of 84.41 m. Following the cutting process, the pieces were transported to the automatic gluing of edge tape sector (sector 18). They were then transported to the drilling section (sector 22), to the cupboard assembly section (sectors 23a and 23b), and to the stock of finished material (sector 13).
The flow lines for the production of drawers (production C), represented by (red) dashed-dotted lines, account for a total of 106.77 m. Following the cutting process, the pieces would be transported to the automatic gluing of edge tape (sector 18), drilling and preparation of drawers sectors (sectors 20a and 20b), then to the assembly sector (sector 21), and to the stock of finished material (sector 13).
The dispatch area (sector 24) was located close to the administration area and to the stock of finished material (sector 13), at the end of the processes described. A linear flow without obstacles could be then observed (27.74 m). The flow of customers took place in the reception, meeting, and production management areas (18.10 m). Figure 4 illustrates the area marked, which represents 195.27 m 2 (as shown in the dashed-line rectangle in black), thus, indicating the return and crossing flow lines, which are critical lines, being highlighted by dark-green circles, representing 66.93 m.
The study identified that the sum of the production, dispatch, and customer flows represented 379.21 m and that the production flow lines (A+B+C) totaled 333.30 m. The need of eliminating return and crossing lines was also identified. With the layout project, the possibility of reducing the The flow lines for the production of cupboards, shelves, and partitions (production B), represented in Figure 4 with (red) dashed lines, covered a total of 84.41 m. Following the cutting process, the pieces were transported to the automatic gluing of edge tape sector (sector 18). They were then transported to the drilling section (sector 22), to the cupboard assembly section (sectors 23a and 23b), and to the stock of finished material (sector 13).
The flow lines for the production of drawers (production C), represented by (red) dashed-dotted lines, account for a total of 106.77 m. Following the cutting process, the pieces would be transported to the automatic gluing of edge tape (sector 18), drilling and preparation of drawers sectors (sectors 20a and 20b), then to the assembly sector (sector 21), and to the stock of finished material (sector 13).
The dispatch area (sector 24) was located close to the administration area and to the stock of finished material (sector 13), at the end of the processes described. A linear flow without obstacles could be then observed (27.74 m). The flow of customers took place in the reception, meeting, and production management areas (18.10 m). Figure 4 illustrates the area marked, which represents 195.27 m 2 (as shown in the dashed-line rectangle in black), thus, indicating the return and crossing flow lines, which are critical lines, being highlighted by dark-green circles, representing 66.93 m.
The study identified that the sum of the production, dispatch, and customer flows represented 379.21 m and that the production flow lines (A+B+C) totaled 333.30 m. The need of eliminating return and crossing lines was also identified. With the layout project, the possibility of reducing the production flow lines in 66.93 m was identified, in order to optimize the movement factor by eliminating critical lines. The flow reduction from 333.30 m to 266.37 m represents up to 20.09% of the production flow lines, which may have a positive effect on productivity in terms of the movement of material and increasing the production capacity and control, as well as reducing the generation of by-products and waste. Figure 5 shows the supply flow lines of the supply of raw materials and production flow lines, taking into account the production centres of each sector.
representing a total of 84.47 m. The location of the storage area (sector 14) hindered the supply of the drilling bench and the assembly line.
The cardboard supply flow lines for the stock of finished material (sector 13) and dispatch sector (sector 24) represented a total of 27.87 m. It was verified that the proximity between the sectors enabled the reduction of the distances covered in the end of the process, as observed in Figure 4 with the continuous line in light blue.
The study identified a total of 396.37 m of supply flow lines in the company, with 309.41 m being for production supply. Figure 5 shows the outline of critical flow lines highlighted by circles in green, which represent 161.43 m in movements, causing delays in the processes.  The sum of the supply flow lines representing the supply of raw material, as well as the input of material, such as MDF, components, accessories, edging tapes, and cardboard, was equal to 86.96 m, as illustrated in Figure 4 by the continuous (pink) lines.
The total of the MDF/MDP supply flow lines for the cutting sectors (15a, 15b, and 15c), CNC machining center (sector 16), and router (sector 17) was of 125.81 m, also taking into account the MDF batch stocked close to the dispatch sector, as shown in Figure 5 with pink, dashed lines.
It was observed that there were edging tapes stocked on the shelves in the automatic (sector 18) and manual (sector 19) gluing of edge tape sectors, as well as batches of edging tapes close to the storeroom (sector 14).
In addition, the distance covered for supplying the automatic and manual gluing of edge tape processes (sectors 18 and 19) was 71.26 m for the respective production centre. The surplus of flow lines can be considered a travel waste, as seen in Figure 5 with the continuous lines in dark blue.
The supply flow of components and accessories for the sectors of manual drilling of drawers (sectors 20a and 20b), for the assembly of drawers (sector 21), cupboard drilling (sector 22), and cupboard assembly (sectors 23a and 23b) is represented in Figure 5 (continuous lines in black), representing a total of 84.47 m. The location of the storage area (sector 14) hindered the supply of the drilling bench and the assembly line.
The cardboard supply flow lines for the stock of finished material (sector 13) and dispatch sector (sector 24) represented a total of 27.87 m. It was verified that the proximity between the sectors enabled the reduction of the distances covered in the end of the process, as observed in Figure 4 with the continuous line in light blue.
The study identified a total of 396.37 m of supply flow lines in the company, with 309.41 m being for production supply. Figure 5 shows the outline of critical flow lines highlighted by circles in green, which represent 161.43 m in movements, causing delays in the processes.
The study also verified the need of eliminating critical supply flow lines (161.43 m). The layout project can reduce the supply flow lines to optimize the movement of materials factor. The flow reduction of 161.43 m represents an overall supply flow reduction from 396.37 m to 234.94 m, that is, a reduction of up to 40.73%, which may increase the productivity of the system, the control of the materials to be processed, and the company's production capacity, enabling it to reduce the waste of production time and delays in delivery.

Information, Production, and Assembly Flowchart with Material Input and Output
The mapping of the production flows from the two technical visits and the zoning analyses, as well as from the assessment of the inter-relationship between the sectors and production, dispatch, customer, material supply, and production flows, resulted in the information flowchart (IF) (Figure 6), prior to the manufacturing process. In addition, the production and assembly flowchart (PAF) was also prepared (Figure 7).  Figure 6. Information Flowchart (IF) (inputs, processes, and outputs).   The manufacturing processes were divided into production flows (A), (B), and (C), as previously mentioned in item 4.1.3. The inputs energy, supply, and material were included in the production supply, as well as the output products, waste, by-products, and information flow.

Production and Assembly Flowchart (PAF) (inputs, processes and outputs)
The project specifications, such as measures and specifications of the material, were pre-established in the sketches of each furniture line, although no formal portfolio of the executive projects carried out by the furniture design specialist could be found to enable better monitoring of the production and respective production waste. The existence of such a portfolio would also give support to innovation products and eco-design or design processes.
The production process took into account customer demand, which started with the verification of the stock of raw material, supplies, and production planning after the client's order. Information regarding the orders made was also cross-checked with the data available in the PPC and stock sectors, being then transmitted to the purchasing sector (first and second lines of Figure 6).
Following the purchase and supply of the material, the orders of service (OS) and cutting plans were executed, which were then sent to the cutting centre (sectors 15a, 15b, or 15c) and CNC machine centre (sector 16) (third line of Figure 6).
With this, it was verified the need of managing and controlling orders, the purchase plan, orders of service, and cutting plans based on the project portfolio. Moreover, it was identified the need of implementing actions in order to optimize the use of energy (which remained switched on throughout the entire technical visit) and the use of paper supplies and toner cartridges, discarded by the company.
The production and assembly flowchart (PAF) is presented in Figure 7 and was designed to describe the flow of the different materials that supplied the production centre, such as MDF, MDP, laminates, cutting discs, edging tapes, glue, oakum, solvents, accessories, screws, nuts, washers, legs for tables, hinges, slides, bubble wrap, adhesive tape, cardboard, and fuel. Electric energy, machinery, and equipment were also inserted.
The production processes (A) and (B) were carried out in the following order: Cutting, CNC machining/router, automatic or manual gluing of edge tape, pre-assembly (drilling and screwing), packaging, dispatching, and assembly at the customer's location. Process (C), the production of chest of drawers, was performed in the following order: Cutting, automatic gluing of edge tape, assembly (drilling, screwing, and assembly), packaging, dispatching, and fitting of drawers at the customer's location, which had a greater volume of components being produced (Figure 7).
The main types of material that supplied the cutting and machining/router production centres were MDF/MDP (first to third lines of the PAF, Figure 7). These centres also produced by-products that were discarded by the company, such as sawdust, shavings, and MDF/MDP waste. These materials were stored in a container (K2), with the sawdust being stored in a silo. In turn, the nylon tapes, used for tying the MDF/MDP batches, were placed together with other material in a container (K1) for disposal. All these by-products were removed from the company's facility by another company specialized in waste collection. With this, the need for optimizing the use of MDF/MDP and reducing the costs of the use of this collection service was verified.
In the gluing of edge tape process (sixth line of the PAF, Figure 7), the cut MDF/MDP panels, edging tapes, glue, oakum, and solvents were the input material outlined. The panels were arranged in wooden platforms, close to the ground, and leaning on workbenches. The edging tapes were placed on shelves behind the machinery. These arrangements pointed out the need for optimizing the space to reduce unnecessary movement of workers within the sector.
The outputs of the gluing of edge tape process were finished panels (consisting of MDF/MDP, glue, and edging tape), by-products of this composition, pieces of edge ribbons, oakum with solvents, glue, and packaging, which were placed together inside a container (K1).
Following the gluing of edge tape process, the furniture pieces remained on hold (waiting) to be transported for assembly, requiring physical space to be stocked (seventh line of the PAF, Production and Assembly Flowchart). The furniture pieces were then separated and transported to the pre-assembly area of tables and cupboards, and to the assembly of drawers sector. The tables could be transported directly to the finished material stock area to be packaged and dispatched, according to the delivery schedule.
The lack of planning and control of the transport of material activity (eighth line of the PAF) obstructed the working area, hampering the movement of people and material during production, causing delays in the production, and, consequently, in delivery.
The outlined input material for the pre-assembly of processes (A) and (B), and for the assembly of drawers (C) (ninth line of the PAF) included taped items, table legs, accessories, screws, hinges, handles, slides, and brackets, as well as electric energy and portable machinery, which could be pneumatically driven or not.
Besides these products, the outputs from the pre-assembly and assembly processes were cardboard boxes from the accessories, the plastic used in the packaging, hardware, and waste from the (manual or bench-type) drill, which could be observed in the workbench or on the factory floor.
In order to prevent any loss of components, the workbenches consisted of MDF boxes attached to the benches for separating the material and shelves on the walls of different heights that would be used to organize the processing material.
The benches also had shelves attached, in order to organize the drawers' components. This organization of the production space had a positive effect on the optimization of the tasks in the sector, highlighting the importance of organizing workstations.
The finished furniture pieces were then transported to the stock of finished material (10th line of the PAF), next to the dispatch area, although they were only packaged after being dispatched for delivery and assembly at the client's space (11th line of the PAF). At this stage, delays in the dispatch procedure and inconsistencies in the deadline were noticed. The inputs of the packaging/dispatch process (12th line of the PAF, Figure 7) were the following: Bubble wrap, adhesive tape, sheets, and cardboard rolls.
The physical space of the packaging sectors, stock of finished material, and dispatch had no trace of dust on the walls or floor or in the air. The space consisted of plastered and painted walls, which facilitated maintenance. Nonetheless, it was observed that the stock of material that had been cut and machined awaited available space in the gluing of edge tape area, to be then transported. Moreover, furniture components were accumulated in the gluing of edge tape area due to delays in their transportation to the assembly area. The detection of these critical routes indicates the need of optimizing and synchronizing the work in the production centres.

Assignment and Destination of By-Products
The process that produced the greatest amounts of by-products was cutting (sectors 15a, 15b, and 15c), as well as the CNC machining center (sector 16), despite the MDF/MDP cutting plans in place. Moreover, it was found that the company did not control the volume of by-products wasted.
The cutting sectors (sectors 15a, 15b, and 15c) and CNC machining center (sector 16) were dusty and filled with by-products on the floor next to the machinery, as well as with sawdust covering the floor and sawdust particles in the air, which had originated from the extraction of the material from the silo due to improper sealing. In addition, the walls of the space were not plastered.
The company had dust collectors with an exhaust system, with the pipes connected to the silo not being correctly connected to the machines, which also contributed to the dispersion of sawdust particles in the air and floor and the on the furniture pieces.
Furthermore, the fact that the extractor (silo) was not appropriately sealed increased the dispersion of particles when the silo was emptied by the company which had been hired to carry out the waste collection and the disposal of sawdust.
In the production line, the furniture company had ducts and collectors to avoid the dispersion of MDF particles in the air. However, the silo did not have a duct system connected to the dumpsters, which, in turn, were not covered to prevent the dispersion of sawdust when being loaded, thus, having an impact in the surroundings.
Moreover, the absence of selective collection of the material was observed. The company did not separate toxic material, such as glue, solvents, and packaging, during waste disposal. Furthermore, oakum waste, sweeping dust, sawdust, and MDF/MDP shavings, as well as MDF/MDP/glue/edging tape by-products, plastic, bubble wrap, adhesive and nylon tapes, and cardboard, among other products which had been specified in the flowchart (Figure 7), were all found together in container (K1), in sector 28. In container (K2), pieces of MDF waste of several sizes could also be found.
Additionally, a need for improving the optimization of the physical spaces could be verified, by clearing the floor, as well as selecting and better handling the waste material. In 2018, a discussion was initiated on the reuse and optimization of waste material, based on the professional experience of the production supervisor that had been hired.

CP Opportunities from the Process Flow Analysis
In order to implement a CP, managers need to envisage the financial benefits which can be generated from saving resources and the environmental impacts associated to the production process, as well as the optimization in the production and supply, which generate internal and external reuse. In addition, the elimination of waste from improved layout planning integrated with CP foments eco-innovation.
Nevertheless, the associated opportunities must be approved and detailed in conceptual plans, so that they can then be implemented through executive projects, with the respective indicators for measurements and monitoring. The flow analysis can be inserted in all stages of the layout project and, when implementing CP in an integrated manner, as an economic and environmental strategy.
The opportunities regarding tools and technologies (O-1 to O-4) promote an improvement in safety conditions and the reduction of risks for workers, minimizing energy consumption, and promoting a preventive attitude of organization and control. They also promote the reduction of time and material waste, minimizing emissions of wood particles in the air, and improving working conditions.
In turn, the opportunities related to process flows, production losses, by-products, and layout (O-5 to O-17) promote a decrease in production time, as well as fewer accidents, minimizing the waste of materials and components and eliminating waste of flow, as well as reducing the consumption of materials and energy and setting out the appropriate setup for selective waste collection. The strategy of using a flowchart map of by-products for internal and external use (opportunity 17) proves to be a form of technological innovation that contributes to better financial performance, as well as greater production and environmental performance of small-scale production.
Finally, the opportunities regarding stock and storage (O-18 to O-21) and suppliers (O-22) help to reduce losses and risks, promoting greater control, enabling breakthroughs for circular economy, as well as promoting and increasing the environmental performance with suppliers and increasing the production capacity. In addition, the opportunities regarding packaging and dispatching (O-23 to O-25) provide a positive environmental position to a company in the market. O-2 Create cleaning and preventive maintenance procedures in the machines and production area.
O-3 Reorganize sawdust ducts and seal the silo from its surroundings. Suggest changes to the waste collection company in terms of covering the dumpster for sawdust collection.

O-18
Store material according to their characteristics and needs to avoid damage, waste and losses. And close to the production areas to avoid waste of flows.

O-19
Facilitate the entry, movement and exit of materials; and stock control and traceability processes, facilitating product Life Cycle Analysis (LCA).

O-20
Optimize the layout of storage spaces to avoid obstruction of floor areas, waste and loss of material and time; seek visual solutions which can be easily controlled.

O-21
Assign shelves for by-products, in order to promote easier handling and reuse for each process, with the shelves being located within easy-reach to other companies, avoiding obstruction of the floor area.

O-22
Prioritize suppliers with environmental certification and from nearby regions, avoiding the generation of gas emissions from transport.

O-23
Optimize the delivery of finished material to avoid unnecessary costs with transport and greater emissions. Use a shared cargo and route system.

O-24
Modify the entrance to the building in order to separate the access for customers from the exit of finished material. Prioritize safety, marketing and information management.

O-25
Prepare a packaging project using Ecodesign and CP principles; and project to implement an eco-seal aimed at the furniture sector.

Discussion
The methodology used for the process flow analysis of the physical space of the industrial facility layout enabled identifying the opportunities of cleaner production (CP) in the furniture manufacturing company (case study), during processing, in the location itself, and in the generating source. The analysis of the process flows can be used in small enterprises in the furniture sector for reducing waste related to the movement of people and material, as well as for decreasing the generation of waste at the source (production waste), so that waste is raised to the category of by-products.
This diagnosis proved to be relevant and consisted of the first step for executing strategic projects aimed at developing a methodological study for implementing CP and continuous improvement actions of flows for the environmental performance of the physical space.
The opportunities for cleaner production (CP), pointed out following the analysis of production, customer, dispatch, and supply flows in the internal space of the company, were considered strategies set out for continuously improving the production processes, eliminating or reducing waste and production loss at the source, and enabling the internal and external reuse of the material. The integration of CP in the process flow analysis of layout projects provides greater opportunity for reducing waste at the generating source, reducing the small company's environmental impact, considering the existing systems and technologies.
The areas wasted with the assignment of by-products for disposal, stock with poor accessibility, and idle circulation can be better used for future expansions. The integration of CP in the flow layout analysis is an innovation strategy, which sets out a greater vision to the future, promoting competition and contributing to a better market position.
As CP monitoring is combined with the application of key performance indicators, the reduction of production flows and movement of material and people, as well as the control of material and stock supply flows, can generate less production loss. The production system becomes cleaner and faster.
The continuous improvement strategy conducted by the methodological approach of the case study, applied to the design of the industrial facilities (layout) from the diagnostic analysis of the flows, indicated a new link with the CP implementation strategy from the preventive point of view, especially considering a small company, which has difficulties in implementing CP and is not charged for the absence of legal rules that require them to be implemented.
It is the strategy of continuous improvement for productivity gain and reduction of productive losses that will drive and encourage the small business to create an organizational culture of CP implementation from the preventive point of view for process optimization.

Conclusions
With the zoning and sectorization analysis of the existing production area in the company in study, 10 wasted or underused areas were identified, which represented a total of 107.24 m 2 , of which 35.79 m 2 referred to the area assigned to by-products for disposal, 45.79 m 2 for stock not close to the respective process, and 25.66 m 2 for circulation areas.
Twelve floor obstruction areas were also identified (39.45 m 2 ), as well as a fragmentation of the storage area, with 15 stock areas for processing material (56.09 m 2 ) and the lack of control regarding the movement of material, which obstructed the circulation and interrupted the flow of material. The rearrangement of the layout areas and flows promotes a reduction of production losses and waste caused by the movement of material and people, as well as improving the production capacity.
Furthermore, it is possible to reduce the stock area from 273.66 m 2 to 188.42 m 2 . The reduction of 85.24 m 2 represents 33.15% of the existing storage area and 6.55% of the total floor area of the current layout. This approximation is based on the elimination of the existing fragmentation of the stock areas, clearing the floor areas, and bringing inter-related areas close to one another.
The reduction of production flow lines from 333.30 m to 266.37 m, by removing 66.93 m of return and crossing flow lines in the circulation area, represents a reduction of up to 20.09%, contributing to a greater optimization of the movement of material and people during the production process, increasing productivity.
Moreover, 396.37 m of flow lines were used for supplying the company, with 161.43 m as a result of the stock being located far away from the respective processes. The reduction of these lines represents 40.73% less in material and human displacements.
The total flow lines identified in the company's layout was of 775.58 m, with process flow analysis enabling us to reduce these lines from 775.58 m to 547.22 m. The reduction of 228.36 m of these flow lines represent 29.45% of the total flow, rationalizing the physical space, and enabling future expansions and gains in productivity. The reduction of flows leads to greater production controls, which enable reduction of the generation of by-products and waste.
Finally, 25 CP opportunities were identified, related to the production area, encompassing the update and optimization of the existing technology, streamlining process flows, and reducing electric energy, production losses, and by-products generated, as well as optimizing cutting plans, the layout of the production areas, production, and transport of the material, the supply chain analysis, and rearrangement of cleaning procedures.
The study showed the need of rearranging workstations, as well as of inserting areas for selective waste collection, with the internal and external reutilization of the material, thus, maximizing resources, by-products, and physical spaces. These changes promote reductions of costs, waste, and production losses, as well as less environmental impact.
The diagnostic process flow analysis associated to CP and applied in the context of a small furniture company demonstrated that the possibility of implementing continuous improvements that promote less waste, applying a CP strategy. The analyses showed that the association of CP to process flows as a preventive strategy leads to a new link between process optimization and environmental performance.
The analyses showed the differentiated positioning of the company management for the systems and technologies, both when monitoring and releasing of information and in positioning the roles of each employee in the production process, highlighting the importance of each person, as well as the skills and characteristics.
People's relationships with physical space and process flows were associated with the attributes of the criterion systems and technologies as a new element that surpassed technical aspects and this application, and demonstrated relationships of belonging and cooperation in relation to the physical space, process flows, and management. These relationships indicated the existence of a link between people, CP, and process flows in the physical space capable of promoting change. It also demonstrated that identifying CP opportunities from process flow analysis can lead to greater engagements, facilitating changes in environmental positioning, and contributing to the reduction of waste and the continuous minimization of waste and emissions.
As there are no legal requirements that oblige small furniture companies to implement a CP strategy, the present study contributed to a change of perception regarding systems and technologies (processes, layout, stock location and control, and movement of people and material) associated to the consumption of raw material and to the generation of waste and by-products, demonstrating that continuous and gradual improvements in process flow performance related to systems and technologies can lead to a more efficient production, generating less waste, and can represent a way of implementing CP in small enterprises.