3.2.1. Process and Activity
Service systems use processes and activities that differ from a business process. Processes and activities cover a full range of situations that might involve highly structured workflows and flexible processes, the sequence and content of which depend on the skills, experience, and judgment of the primary actors [
37]. As mentioned in
Section 2.1, SLA is the guarantee of the service provider to provide service for customers. Under the constraint of the SLA, the candidate primitive services in the repository for each service can be divided into different service sets, and the service process and activities matching the requirements of the customer can be constructed quickly. Customer requirements are the driving force of a service system, and services, including processes and activities, are dynamically constructed. As shown in
Figure 2, for customer service requirements with the same function and different SLAs, the provider will select different primitive services from the service repository to form different service processes and activities. Usually, a primitive service is used to complete an activity in the service process, and there is a one-to-one relationship between them. When a process contains a sub-process, the sub-process can be regarded as an activity of the parent process, and the service used to implement the sub-process may be a primitive service or complex service. Since the structure of the parent process and sub-process are consistent, we can ignore the sub-process and treat it as an activity. For example, if a customer wants to send a package to a destination, taking the postage and delivery time as SLA parameters, the delivery time will be longer if the price is lower. Then, for a low postage package, a vehicle should be used to transfer it from one station to another station until it reaches the destination; for a high postage package, for the package with high postage, air transfer should be used to reduce the delivery time. From the perspective of the customer, what he wants is a complete service, and he does not care about the service process and activities. Therefore, if the customer pays
$5, the package should arrive at the destination within 5 days; if the customer pays
$10, then the package should arrive at the destination within 3 days. From the perspective of the service provider, they need to understand the whole service process and activities, and the appropriate primitive services should be selected to complete the corresponding activities or tasks, which may be the provider’s own or outsourced to other participants. So in order to deliver the customer’s package to the destination, the service provider may use a logistics company’s vehicle to transport the package from one place to another until it arrives at the destination; it may also rent space on an aircraft flight to transport the package to the destination.
To meet the need of the customer, each service needs to combine different primitive services, which represent specific activities or tasks in the service process. Therefore, each service process is composed of different activities, which are executed to complete the whole service. In the service process, each activity needs to be fulfilled by at least one actor, including the customer, service provider, and other participants. By completing these activities together, the actors (co-)create value, exchange value, and meet their own value expectations.
3.2.2. Definition of Some Concepts
Based on the above description, in this paper, some concepts related to the service process value model are defined as follows:
Definition 1. Business process is a series of activities completed by people, organizations, or automated resources to achieve specific goals.
Definition 2. Service Process is a series of activities completed by people, organizations, or automated resources to provide specific services to the target customer.
The similarity between service process and business process is that there are not only strict sequence restrictions among activities, but also the contents, methods, and responsibilities of activities must be clearly arranged and defined, so that the activities in process can be transferred between different actors. An activity in a business process, and a service process, can represent a sub-process, and the process can be nested. Business process is generally used to describe the collaborative production process of products, while service process describes how to deliver services to customers, to meet their requirements. Therefore, business process is product-oriented, and service process is customer-oriented. However, with the gradual evolution of servitization, the differentiation between products and services is increasingly blurring [
38]. Lusch [
32] argued that products can be seen as service distribution or provisioning mechanisms. Based on Banerjee’s argument of “everything as a service” [
39], we further argue that the production process of a product can be a service process, or a part of a service process, the difference lies in whether it is customer-oriented. Hereby, if the business process is customer-oriented, it can be a service process, otherwise it is part of the service process.
Therefore, for non-customer-oriented business processes, based on the MDA method mentioned in [
40], we can transform a business process into a service process. When constructing a service process model, we also need to consider the impact of some characteristics of the service domain on service process. In the service domain, the service ecosystem has formed its unique service domain characteristics in its long-term development and evolution process; mainly including apriority, correlation, and similarity [
41].
3.2.3. Building a Service Process Model Based on Process Mining
Through the traditional modeling method, we can build the service process model by observing the service process and activities in the service process, and by combining them with domain knowledge, manually or using modeling tools. However, the service process obtained in this way is relatively rough and may be different from the actual implementation of the service process. The observation is not accurate enough, and many hidden details may not be obtained through observation. To describe the model more accurately, we use a method based on process mining to build the service process. Normally, many raw data and event logs related to services are stored in the information system. If there are enough traces in the event log, the process and activities obtained by process mining will cover a full range of situations. As shown in the dotted box in
Figure 3, there are two ways to build service process using process mining, based on raw data and event logs: one is from the business process model (BPM) to the service process model (SPM); the other is from the enriched event log to the service process model.
The raw data and event logs stored in the information system are the basis for building models. As mentioned in
Section 2.2, the event logs need to be preprocessed and saved in XES format. By using the corresponding algorithm in process mining, such as the α-algorithm, we can get the business process model (control flow model), represented by Petri net. Since a business process is not customer-oriented, we need to transform it into a service process. In this way, we first get the business process model and then transform it into a service process model. In the transformation of the models, domain knowledge and domain characteristics should be considered.
In this way, since the raw data and event logs do not contain the behavior information of customers in the event or activity, we also need to preprocess them, and supplement the customer-oriented information with domain knowledge and domain characteristics. Hereby, we get the formatted enriched event log. Then we can directly extract the service process model by mining the log. Since the model we get is already customer-oriented, it is a service process model, and it does not need to be transformed again.
In this paper, we just use process mining as a necessary tool to help in building a service process model. As for how to extract the process models from logs, this paper is not concerned. Many scholars have done a lot of research on how to extract the process model from the event logs, through process mining, which is mentioned in
Section 2.2.
The service process model is a transition model that prepares for the service process value model. So, after getting the service process model, we need to construct the service process value model based on it. As shown in
Figure 2, combined with the additional value information captured in the raw data and event logs, and the knowledge of domain experts or human experience, the value annotation is attached to the service process and it is converted into a service process value model. In fact, value is annotated onto the activities of the service process, because value is created through activities. In addition, domain knowledge is closely related to the field of service. For example, for the maintenance of mobile phones, customers usually send the mobile phones that need to be fixed to a designated maintenance point for repair; while for air conditioning maintenance, maintenance personnel are required to provide maintenance services on site. Although they are all maintenance services, there may be great differences in domain characteristics. Therefore, domain knowledge has an important impact on the value of activities.
Hereby, the service process value is based on service process model, and it not only focuses on the cooperation relationship among actors in the activities or process, but also emphasizes the value creation of actors in the activities. Value is the core of service process value, and activity is just a means to support the realization of value. In other words, satisfying the customer’s value expectation is the core of the service process value model, and service process is the basis to realize the value expectation. Our focus is on how to add value information to the activities in the service process. Next, we will describe and define the concept of value in service.
3.2.4. Value in Service
Value is the goal pursued by both sides, the service demander and service provider. Both sides create value through working together in the service process to meet their respective value expectations. Generally, different service actors have different value expectations.
Owing to different concerns, different people may define value from different perspectives. Allee [
42] argued that there are two types of value, tangible and intangible value. Therefore, we further argue that value is multidimensional, and that the value creation and value expectation of each actor may only contain some of these dimensions. For example, value can be defined from the perspective of economic benefits, product acquisition, resource used, and customer experience, etc. In this paper, in order to distinguish the value creation of the different actors, in service process and activity, we use three dimensions to define service value: time and space, profit, and experience, as shown in
Figure 4.
The time and space dimension refers to the requirements of service value creation in time and space, which can be realized only by meeting the requirements. It is closely related to the activities in the service process. For example, in a logistics service process, a certain amount of time is spent to transfer a package from one place to another; in a product manufacturing process, it takes a certain amount of time to turn some materials into parts. The time and space dimension reflects the time consumption, and the change of location or status, in activities. The profit dimension refers to the benefits obtained by actors in the service activity, including economic benefits, physical products, information, etc. It is related to the service actors because each actor in the service process, including the customer, benefits from it. For example, in logistics service, the customer’s package arrives at the destination, the logistics company gets the freight, and the truck driver gets the reward; in product service, the customer gets the product he wants to buy, and the manufacturer and the material supplier gain the sales income. The experience dimension refers to the intangible value or impact of the service process or service results, including knowledge, corporate reputation, social impact, customer satisfaction, experience, and skills, etc. The experience dimension is related to the effects of the service process or service result. For example, in a logistics service, as the logistics company delivered the package to the destination earlier than expected, customer satisfaction increased, and the reputation of the logistics company also improved. In addition, the cube symbolizes three dimensions of the value, and the creation of value is inseparable from the use of resources in the process of service. These resources can be people, vehicles, tools, materials, spare parts, products, data, etc. Considering the complexity of the impact of resources on value creation, this aspect will not be discussed in the paper for the time being but will be carried out in the future research work.
Based on the above description, we define value in service as follows:
where
vts is the time and space dimension of V,
vp is the profit dimension of V, and
ve is the experience dimension of V. If a dimension has no value, we use “ ” to represent it. Therefore, the format of V is a triple and some places of it might be empty. For example, if the working time of a staff member, A, is two hours in the service, his value can be expressed as
v = (2 h, , ).
As we mentioned previously, services are customer-oriented. The service process is implemented around the requirements of customers. The process of the provider providing services to the customer is shown in
Figure 4. The activities in the service process may be parallels, loops, etc., which will not be considered here, but only the process of the service moving closer to the customer. We can find that the value of service has a different granularity. Value in the service economy is driven and determined by the customer [
43]. From the perspective of the whole service, the entire service process is customer-oriented, so it is the maximal granular value. In the service process, the activity for completing every specific task will create value, which is the minimum granularity of value. Some activities are fulfilled by the service provider itself, and some activities are outsourced to other participants. As shown in
Figure 5, six activities are outsourced to other participants, and the number of activities completed by each participant may be different. How participants complete these activities is transparent to the service provider. Service providers do not need to know how, but the participants themselves should know. These activities can be regarded as sub-processes in the service process. For example, a service provider wants to transport a package from one place to another. It can outsource the activity to a transportation company. It does not need to consider how the transportation company completes the activity. Then, we can take the value generated by activities which are completed by participants as the medium granularity value. Therefore, there are three kinds of granularity value in the service, that of large granularity value for the customer, medium granularity value for the participant, and small granularity value for the activity. Of course, the value granularity of the service provider is the same as that of the customer.
In the actual service process, an activity may be completed by multiple actors, and each actor completes different parts of the activity. Due to the complexity of some activities, a single actor is unable to complete them. For example, in the air conditioning installation service, two people are needed to complete the external unit installation; in the air conditioning maintenance service, when the spare parts need to be replaced, the spare parts provider and worker need to participate in the activity together. This situation will be considered later in this paper.
3.2.5. Construction of the Service Process Value Model
Activity is the basic unit of the service process, which completes the specific task in the service. Activity is also the basic unit of value creation in the service. If an activity does not generate value, then it does not need to exist in the service process. As shown in
Figure 6a, from the perspective of only one actor in the service, each activity has an input value and an output value.
Vin represents the input value of the activity, and
Vout represents the output value of the activity. In normal circumstances, the output value of an activity should be greater than the input. However, there are also exceptions, such as in the production process, the probability of waste products is inevitable, so the value generated by a certain activity is less than the input value. As mentioned in
Section 3.2.1, the value of activity may be tangible, intangible, or both. Therefore, we can use the time and space, profit, and experience dimensions to express each specific value, whether it is input value or output value.
An activity can be completed by one of, the service provider, customer, and other actors, or it can be done by multiple actors. For the same activity, its input value and output value may be not the same in different situations. That is to say, the value of
Vin and
Vout will be different when the performers of an activity are different. For example, if a product is sold by a manufacturer or by a retailer, the cost will be different, and the price of the sale may be different. Therefore, the value creation of activities is inseparable from the actors. In essence, it is the actor who achieves value creation in the process of performing the activity. As shown in the
Figure 6b, each actor has an input value and an output value on the activity they participate in. If multiple actors participate in the same activity, each actor creates their own value through the activity. As shown in
Figure 6c,
Actori and
Actorj work together to complete the activity, the input and output values of
Actori are
and
, and those of
Actorj are
and
. For example, there are two actors, the manufacturer and the customer, in the activity of selling products directly by a manufacturer. For the manufacturer, the input value of the activity is the product, the output value is the money paid by the customer; and for the customer, the input value is the money, the output value is the product. Of course, both actors involved in the activity need a certain amount of time to complete it. These values are the only tangible values that we can observe. Since the service provider can improve its reputation through the product quality, and the customers get the products, they also get spiritual satisfaction at the same time. Hereby, the output value of the manufacturer may also include corporate reputation, and the output value of customer should also include the satisfaction of the requirement.
The service process is composed of activities in a certain order to fulfill the requirements of customer. Then, based on activity value, we can get the value of the service process. However, service systems are complex adaptive systems, and they are dynamic and open [
5]. As such, the service processes are dynamic, and the activities in the service process are also dynamic. In the current market competition environment, the division of labor and cooperation is very common. Since the customer wants a complete service, the service provider needs to integrate the primitive services of other actors into a complex service to meet the needs of the customer. In other words, under the coordination of the service provider, different actors will participate in the completion of different activities, and each activity may have multiple actors competing for participation. Therefore, the customer-oriented service process needs to be completed by multiple actors. As shown in
Figure 7, there are five activities in the service process. An activity in the process can be executed by different actors, and an actor can also participate in different activities. For example, in
Figure 7, on activity A, there are three actors involved; the service provider or
Actork can complete the activity C, activity D, and activity E,
Actori is in competition with
Actorj on activity B, and
Actori can cover activity B and activity C. We only show the three participants in the figure, and of course there are others. We just ignore them for the convenience of the figure display and introductory purposes. Since the value of the activity will be different when the performer of the activity is different, the value of the service process also will be different. The service provider can dynamically adjust the service process, according to the customer’s value expectation, to meet the requirements.
Another important feature of the service process can be found in
Figure 7, which is that the service process is triggered by the customer and ends with the delivery of the service to the customer. This is one of the important differences between service process and business process, because the starting point of service is to meet the requirements of customers. It is also possible that the service provider needs to do some aftercare work, after the service is delivered to the customer, such as archiving the service-related information.
Based on the above analysis, we can start to build the service process value model. As mentioned in
Section 3.2.3, no matter which method is used to build the service process model, the related event log of the target service and process mining algorithms are the necessary foundation. For the event log, if it has been saved in XES format, we can use it directly, otherwise, we need to process it according to the standard of the XES format, so as to prepare for the subsequent work. For the process mining algorithms, there are many algorithms for process mining, which have been mentioned in the relevant literature, and we will not repeat them here. Here we mainly use the α-algorithm, or its improved algorithms, for mining. To extract the actor(s) and the corresponding value of each activity from the raw data and event log, we need to add new functions to the existing algorithm tools or develop a new tool. At the same time, we need to combine domain knowledge or user experience, such as the apriority of service, that is, experience knowledge generated in over the long-term service process. Since the service process model is the abstraction of many concrete service processes, the value of each activity here is an average value, or a value range. Furthermore, as the model obtained by process mining is described as a Petri net, activities in the service process are mapped to the transitions in it. We need to add the actor(s), the input value, and output value of the activity to the corresponding transition, as shown in
Figure 6b,c. To describe the construction process of the service value model in a formal way, we define business process model, service process model, and service process value model as follows:
Definition 3. Business process model is a business petri net N = (P, T, F), where
P is a set of places;
T is a set of transitions, representing activities;
F ⊆ (P × T) ∪ (T × P) is the flow relation describing the arcs between places and transitions (and between transitions and places).
Definition 4. Service process model is a service petri net SN = (P, T, F, ts, te), where
P, T, and F are the same as in the business petri net N;
ts ∈ T, ts is the first activity of the service process and triggered by the customer;
te ∈ T, te is the activity of service delivery completion, and the customer must be the actor of it.
Definition 5. Service process value model is a service value annotated petri net SVAN = (P, T, F, as, ae, A, V), where
P, T, F, ts, and te are the same as in the customer-oriented service petri net SN;
A is a set of actors, ∀a ∈ A, a can participate in at least one activity ti;
V is a set of values, V ⊆ (A × T) ∪ (T × A) is the input value and output value between actors and activities.
Let raw data be D, and event log be L, then take the “from BPM to SPM” path as an example, the steps of building the service process value model are described as follows:
Input the event log, L, to generate a business process model, N, by using process mining techniques.
Check the first activity in N, if the value of the “org:resourse” is a customer, then add the customer as the actor of it, and make it as ts of the service petri net SN; or else add an activity, ts, as the first activity of the whole process, and take the customer as its actor, and consider whether the co-actor exists in it or not.
Check the activities in N, if an activity to complete the delivery of the service, then add the customer as the actor of it and make it as te of the service petri net SN; or else add an activity, te, in the appropriate position in the process, take the customer as its actor, and consider whether the co-actor exists in it or not. Then generate the service process model SN.
Check all activities in SN, to extract the value of the “org:resourse” from the raw data, D, and event log, L, then get the set of actors, A;
Combined with the domain knowledge, check the input value and output value between actors and activities in SN, to extract the set of values, V, from the raw data, D, and event log, L.
To annotate the value set V between actors in A and activities in T of the service process model SN, then get the service process value model SVAN.
As shown in
Figure 8, this is the general form of the service process value model. There are five activities and six actors in the model. The first activity is A, which is completed by two actors, that of the Customer and Actor1. We used a dashed box to enclose the Customer and Actor1 to indicate that they are working together to complete the activity. Since the customer’s service requirement is the trigger of the process, we put the Customer in front of Actor1. Both the Customer and Actor1 have input and output value in the activity. Activity B is completed only by Actor2 and activity C is completed by Actor3 and Actor5 together. Activity D can be performed by Actor2 or Actor4, which is not cooperative, but alternative. Finally, the service needs to be delivered to the customer, so activity E needs to be completed by Actor5 and the Customer together. Since the customer is the receiver of the service, we put the Customer after Actor5. The service process starts from the customer’s service demand and ends at the service delivery to the customer. Every activity in the service process is involved in value creation.