A Design Process Model and a Computer Tool for Service Design

Proceedings of the ASME 2007 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference IDETC/CIE 2007 September 4-7, 2007, Las Vegas, Nevada, USA

DETC2007-34991

A DESIGN PROCESS MODEL AND A COMPUTER TOOL FOR SERVICE DESIGN Yoshiki SHIMOMURA* Department of System Design Tokyo Metropolitan University Minamiosawa 1-1, Hachioji-shi Tokyo, Japan [email protected]

Tomohiko SAKAO Institute for Product Development and Machine Elements Darmstadt University of Technology Magdalenenstrasse 4, 64289 Darmstadt, Germany [email protected]

Erik SUNDIN Department of Management and Engineering (IEI) Linköping University SE-581 83 Linköping, Sweden [email protected]

Mattias LINDAHL Department of Management and Engineering (IEI) Linköping University SE-581 83 Linköping, Sweden [email protected]

ABSTRACT Manufacturers at present face new circumstances in terms of consumer services and serious environmental problems. An effective way to deal with these circumstances may be to pursue qualitative satisfaction rather than quantitative sufficiency. The aim of this paper is to demonstrate the effectiveness of Service Engineering, including the service design process model, to increase customer satisfaction. The redesign of services offered by a global warehouse manufacturer is used as an example of the application. Four redesign options, such as rapid delivery of components and a robust electrical system, were generated. The effectiveness of the method was demonstrated by the application.

create value by coupling a product and a service, have been attracting attention. However, because few studies have focused on the design of a service (e.g., [3, 4, 5, 6, 7]), the authors carried out fundamental Service Engineering (SE) research by examining services from the viewpoint of engineering [8, 9, 10]. The aim of SE is to provide a fundamental understanding of a service as well as concrete engineering methods to design and develop a service. This paper first proposes a concept of service design and a computer-aided design (CAD) system referred to as a Service CAD. Next, a method to model and design a service with the Service CAD is proposed. Finally, the effectiveness and feasibility of the proposed method are verified by an industrial case study.

INTRODUCTION As society matures, services and knowledge are increasingly important in many industries [1]. In manufacturing, the service and knowledge provided through a product are regarded as more important than the product itself. As a result, “Product-Service Systems (PSSs)” [2], systems that

LIMITATIONS OF CURRENT PRODUCT-CENTERED MANUFACTURING A number of methods and tools for highly functional products design have been developed, and many have become available on the market as production industries have become more conscious of high technology; however, very few of the

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Professor and author for correspondence, Phone: +81 (426) 77-2729, Fax: +81 (426) 77-2729, E-mail: [email protected]

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one consumer to another; thus, consumer modeling for design activities is crucial since most mass production currently deals with the flat recognition of various consumers. SERVICE DESIGN AND SERVICE CAD

Figure 1: Design operations with constraint between product and service. products have been accepted by consumers. Producers stick to their own views of customer value in developing their products even though advanced technologies have been incorporated successfully. In other words, producers incorporate advanced technologies as the royal road to designing a physical structure for a requested functionality, which is one of the reasons highly functional production in many cases does not promote sustainable market growth. Producers should be aware of how to carry out business activities which realize sustainable market growth. The concept of value is crucial because it is the interface between consumers and producers. This concept, in the context of creating high added value, is better explained using the metaphor shown in Figure 1. The point is that there is too much focus on physical products without services. In Figure 1, the plate is a design object, while two bars fitting through the holes of the plate represent the axes of product and service, which are regarded as important factors constituting a design object. The holes have a small play around the bars. If a product alone or a service alone is designed, the total value is not considerably increased (Operations 1 and 2, respectively). By designing a product-and-service set, the total value increases. It is true that many methods dealing with service exist in management [11]. However, very few methods provide a high value for customers by designing services in parallel with designing products. The general trend is that the demand for services outweighs the demand for physical products as economies mature [8]. However, it is obvious that value is a concept that varies from

Service Design In general, a service is an activity that responds to customer needs. In addition, service design often means only the specification of the behavior of service staff, even when some products are strongly related to the service contents. In this study, the objective of service design is to realize the structures required for the provision of the service, including the design of a product used to render the target service. The design process of a conventional service consists of three sub-processes: the analysis of the customers, the design and development of products and services, and test marketing [12]. Marketers analyze customers and perform test marketing, while engineers perform the design and development of products needed to provide the target service. Service design based on this design process has the following two problems: 1) Different design actors Because the analysis of customers and the design of products are performed by different actors, it is not easy for product designers to understand customer needs. In addition, it is impossible for product designers to obtain feedback regarding design solutions in one design cycle. 2) Separation of product design and service design In many cases, a product designer brings a task to a close when a product fulfills a generalized role, but the designer does not take into account the product’s real value for customers. In other words, customer satisfaction may not be fully achieved because the processes of identifying the value of a product for customers and specifying a product’s structure for the value are separate. The objective of this study is to solve these two problems by integrating product design and service design so that a single actor can carry out the core processes. In the integrated process, the service designer designs a service by alternately repeating the analysis of customers and the conceptual design of a service. The service designer can then realize an effective and precise conceptual design to specify the realization structure of a service and meet customer’s requirements. Service CAD The solution space of service design can be much broader than that of the conventional product design, which makes the derivation of design solutions difficult.

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Service Design Process Organizer

Service Evaluator

Figure 2: Conceptual scheme of Service CAD. In this section, a computer-aided design (CAD) system for service design, called a Service CAD, is introduced to provide computerized support for service design. The results of service design, including the quality of the solutions and the efficiency of the service, depend largely on the designer’s knowledge and methods. Issues regarding the management of design in various fields have been discussed. Research into knowledge-based CAD (e.g., [13]) is one research field where such issues have been tackled. According to studies, knowledge of design is important when using CAD systems to derive a creative design solution. In other words, it is desirable for a CAD tool to support the design of a completely new solution that could not be conceived by one designer relying on his or her knowledge and experience alone. By providing design knowledge based on existing service cases and realizing a partially automated design operation, a Service CAD can facilitate competitive service design and development. An analysis of existing service designs revealed that most service designs fall into the following categories [9]: (1) (Re-)design of a new service by enhancing components of and improving existing services, (2) application of existing service to a different field, and (3) creative new design. For the first two categories of service design, the success or failure, the quality, and the efficiency of service design depend largely on knowledge of service design and existing service cases. However, a systematized knowledge base of service design hardly exists, while in mechanical design, the existing design knowledge base can be stored in a reusable form. In the first categories of service design, there are at least three patterns of operation [9]: (1-1) Substitution of components, (1-2) removal of a part of service, and (1-3) combination of different existing services. Pattern (1-1) is an operation in which a component of an existing service is substituted by another. Patterns (1-1) and (12) are operations to build a new service by changing and modifying an entire or a partial structure of the target service, while Pattern (1-3) creates a new combination of services.

Based on the above-mentioned analysis, we have proposed the concept of a Service CAD [9] to support engineers in designing services. A Service CAD serves as an environment which aids in the development of a service by providing information about existing service cases and various operational rules stored in the database. Figure 2 shows a conceptual scheme of a Service CAD, which consists of the following components: (a) Service case base: A database of existing service cases. (b) Design rule base: A database of operational rules for service design. (c) Reasoning engines: Reasoning engines which analyze various properties of service, such as similarities. A pluggable mechanism is employed so that the necessary reasoning engine is selected based on the designer’s request. (d) Service evaluator: A module to evaluate a service design solution. (e) Service design process organizer: A module to support service design processes based on a specific design methodology by means of other components. The Service CAD presented in this study is programmed to collect existing service cases. In addition, the Service CAD reuses design rules derived from the design procedures of previous service design cases and registered as information used to operate and modify other service design cases in a database. By applying the design rules to all or part of a service in a partially automated manner, the time required for service design can be reduced. In other words, one of the methods to design a new solution is to apply various sets of design rules to existing service cases. This study suggests a reasoning mechanism using service case databases and several reasoning engines to realize various design operations as a fundamental element of the Service CAD. The prototype system of the Service CAD, called Service Explorer, has been developed. The system has the following five functions: (I) To allow a user to input and edit a service model, (II) to display component elements on which designers focus, (III) to register service cases in a service database, (IV) to search in the service database, and (V) to reuse service model data stored in the service database. The requirements and details of the implemented specifications are as follows. (I) To allow a user to input and edit a service model This is the most fundamental function of Service Explorer. In order to acquire information about service cases for efficient service design, an easy graphical interface to describe a service model is needed. A service model is described as a graph structure consisting of nodes and arcs.

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Figure 3: Screen Images of the prototype Service CAD system. (II) To display component elements on which designers focus The system must selectively display component elements depending on designers’ demands so that they can understand the structure of the service. Service Explorer provides a function to display the function topology and the parameter structure. (III) To register service models in the service database Because it is desirable that the service database store service cases independently of the specific OS/application, Service Explorer employs XML as the database description language. (IV) To search the service database

Figure 4: Definition of service. Service Explorer is equipped with a search function to look up the service database depending on each designer’s requests. Using the current Service Explorer, designers can search for service models with keywords contained in the composition elements (for further details, see “MODELING METHOD WITH THE SERVICE CAD”). (V) To reuse service model data stored in the service database This function allows composition elements to be reused or the structure of a service model to be stored in the service database when a designer inputs and edits a service model. Based on the above-mentioned functional specifications, Service Explorer has been developed in Java SDK 1.4.1 and XML version 1.0. The MVC model [14], which has been used widely in general GUI applications, was adopted as the basic architecture of Service Explorer. By applying the MVC model, the high flexibility and reusability of Service Explorer and the robustness of the service model data were achieved. Figure 3 shows screen images of Service Explorer currently under development. To realize the Service CAD system, a service modeling method to describe and operate a service in a computer is needed. In addition, it is necessary to clarify the requirements for the design aid with the Service CAD by clarifying the service design process and its sub-processes. In the next chapter, the service modeling method is explained. MODELING METHOD WITH THE SERVICE CAD Components of a Service In Service Engineering, a service is defined as an activity by a service provider to change the state of a service receiver [10]. A service is delivered by means of service contents and service channels. Service contents such as materials, energy, and information directly change the receiver’s state. A service channel transfers, amplifies, and controls service contents and indirectly influences the state change of a service receiver (see Figure 4). Service contents and channels make up the realization structure of a service. Service design is a process of clarifying the realization structure to fulfill a requirement; it is the same as the existing

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Figure 5: Three kinds of service models: flow model, scope model, and view model. formalization for product design [15, 16]. In existing design research, it is commonly agreed that functions are the fundamental lexical expressions to represent the role of a design object. The general design is achieved by the operation of correlating realizable physical structures to the functions; therefore, it is assumed that the functional representation is applicable to the representation of the state change of a service receiver, the contents, and a channel. In this study, it is assumed that a service and the state change of a service receiver can be expressed as the combination of parameters that represents the service and the relationships among the parameters. In addition, three parameters to express the state change and represent the influence of a service are suggested. First, a receiver's state is represented by a set of Receiver State Parameters (RSPs). Any RSP can be defined if it describes a receiver’s state; however, for meaningful design to be realized, RSPs must be observable and related to the needs of a service receiver. The adequate representation of a service receiver’s demands with RSPs is one of the most important processes in service design. In addition, the parameters expressing contents are called content parameters (CoPs). In the same way, the parameters of a channel, which affect the content parameters and indirectly influence RSPs, are called channel parameters (ChPs).

Sub-models of a service A service can be observed from various points of view depending on the service receiver and provider; therefore, all possible viewpoints should be taken into account when a service model is defined. In this study, the three sub-models of view, scope, and flow are proposed to describe a service (see Figure 5). (1) View model A view model describes a functional structure to realize a change in an RSP and expresses a part of the realization structure of a service through the relationship between the RSP and the functional structure, described in the form of the functional relations among the RSP, CoP, and ChP. The functions of channels and contents are expressed by function names (FNs) as lexical expressions, function parameters (FPs) as target parameters of functions, and function influence (FI) as the influence of a function on FPs. Each function is related to another. The FPs that are directly related to RSPs are recognized as CoPs, and those indirectly influencing RSPs are ChPs. The most important role of service design is to clarify the realization structure of a service represented through the relationships among the abovementioned parameters (RSP, ChP, and CoP). In addition, by relating the realization structure composed of CoPs and ChPs to artifacts, the roles of actual artifacts in a service, as a channel or contents, can be observed. (2) Scope model Since an actual service has quite complicated structures composed of mutually related providers and receivers, it is necessary to specify the active target range in the design of the service. A scope model expresses the target range of a service, as illustrated in Figure 5. A scope model is represented as a set of RSPs and view models that are related to them. By focusing on the relationships to RSPs, the service designer can recognize the relationships among sub-services. (3) Flow model As mentioned above, many services form complex structures consisting of many agents. Between a receiver and a provider, there may be many intermediate agents. It is generally inefficient to provide a service without the support of these intermediate agents. Since intermediate agents also evaluate services as service receivers, values prepared for intermediate agents must be also designed. In this study, we call the chain of agents a flow model. A service designer needs to integrate the evaluation of multiple receivers to increase the value of a service.

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then return to this step after determining the details of the steps described below. Step 2: Extraction of RSPs of a Service Receiver In this step, RSPs, the target parameters of a service, are extracted from the state parameters in the scenario specified in Step 1). The main goal of the service design based on this design process model is to develop the realization structure of a service to realize the change of these RSPs. With this step, the service designer can determine the basic requirements of a service: the receiver of the service and the value the service has for the receiver.

Figure 6: The proposed design process. SERVICE DESIGN PROCESS FOR THE SERVICE CAD In this chapter, the required service design process is clarified based on the service model explained in the previous chapter. The service design process model is formalized as shown in Figure 6. Each step of the design process model is explained. In the following explanation, the focused service provider is called the initial provider; the final receiver of a service is called the end receiver; and all the receivers in a service model, including the end receiver, are described as service receivers. Step 1: Development of an Initial Flow Model In the service design process model, the service designer develops an initial flow model in reference to the existing design cases. Agents in a flow model are determined by defining new agents or by choosing them from the agent database, which is used for registering prototypes of service agents. The agent prototypes include a set of scenarios representing the behavior of an agent. A scenario describes a service receiver’s actions in the form of a state transition graph. To improve the existing service, a flow model of the existing service is developed in this design step. Then the service designer describes the existing scenario for the target service and modifies it as appropriate. In designing a completely new service, the designer can develop a simple flow model composed of only an end receiver and an initial provider and

Step 3: Development of a Realization Structure for each RSP In this step, the service designer determines functions to realize the state change represented by RSPs and develops realization structures to realize these functions. The realization structures are arranged for the whole service structure expressed by the flow model. To set up realization structures, the service designer can refer to or apply function prototypes, the relations between RSPs and function prototypes, and the relations between function prototypes and the agents, which are stored in the realization structure database. Figure 7 shows a small part of the developed model for an illustrative global warehouse manufacturer service (for details, see “AN APPLICATION OF A SERVICE DESIGN TOOL AT A WAREHOUSE EQUIPMENT MANUFACTURER”), corresponding to the RSP function availability. A function prototype is the design information which represents the correspondence between a function and a realization structure [17]. Utilizing function prototypes, the service designer can recognize, for example, that the RSP “cleanliness of clothes” can be influenced by the realization structure of the function “washing clothes,” including the entity “washing machine.” In addition, according to the correspondence between the function prototype and the agent to realize that function, the designer can recognize that a home appliance manufacturer can provide the realization structure of the washing function. If the realization structure database does not include an applicable function prototype, the service designer can develop and use a new realization structure. In addition, if several realization structures and agents are applicable to a certain RSP, the service designer can prioritize several candidates for possible realization structures. The realization structure does not need to be provided by the initial provider; other providers may take the role. Through this step, the service designer can arrange the candidates of the means to realize the target service. Step 4: Assessment of the Feasibility of the Developed Realization Structure The service designer determines whether the candidate realization structures prioritized in Step 3) are applicable to the target service. The designer has to check not only the fulfillment

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Figure 7: View model used to generate design solutions.

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has been arranged in the upper stream or in the lower stream of an initial provider. If a new agent has been set in the lower stream, it is necessary to design a new realization structure for the new agent. For this purpose, the service designer should return to Step 3) to redesign the flow model and the realization structures. For example, when a retail store is set in the lower stream of a washing machine manufacturer, a realization structure to adequately fulfill the RSPs of the retail store is required. If a new agent has been set in the upper stream, a service provided to the new agent does not have to be considered. Through this step, candidates of the flow model are developed. Figure 8: The flow model of warehouse equipment supplier and its customer [19]. of each RSP but also the total feasibility of the entire realization structure to change all the RSPs. Step 5: Judgment of the Existence of a New RSP By composing the realization structure for a service, new RSPs which can be fulfilled by a service are often found. In this step, the service designer searches the realization structure database to investigate whether other state changes might be realized by the realization structure. For example, by applying the realization structure of a taxi to a transportation service, a new RSP, “occupation of a space,” can be recognized in addition to the RSP “transportation to a destination.” In this step, a receiver’s state change is analyzed again based on the developed intermediate solution. Such a reanalysis is one of the characteristics of this design method. Step 6: Placement of New Agents / Create a New Flow Model In this step, the service designer checks whether a new agent should be added to Step 3) and determines adequate positions for the agents in the flow model identified in this step. In addition, the service designer checks whether a new agent

Step 7: Selection of a Flow Model In this step, the service designer selects the best flow model from the candidates derived in Step 6). It is necessary to determine whether the required values in a flow model have been satisfied by calculating the sum of products between the evaluation and the importance weighting of each RSP [18]. For this purpose, the priorities of service receivers and their RSPs are determined first. The priorities of several service receivers in a flow model and their RSPs can vary depending on the strategy of the service design. In this step, the service designer gives the importance weighting of each service receiver and its RSPs based on the business strategy and the result of customer surveys. As an evaluation criterion of the fulfillment of each RSP, the ratio of the value for each service receiver to the cost borne by the receiver can be suggested. AN APPLICATION OF A SERVICE DESIGN TOOL AT A WAREHOUSE EQUIPMENTS MANUFACTURER In this chapter, the design method presented above is applied to an actual service. The application of a service design tool at BT, a global warehouse supplier, is the design object. The main objective of the warehouse supplier is to develop a service that supports customers’ material handling operations.

Cost for warehousing Time for delivery

Capacity change Function availability Fleet/system operation

Identification of customer

Contract preparation

Fleet preparation

Fleet delivery

Initial fleet/system installation

Fleet/system maintenance

Fleet/system Take-back

Fleet/system installation

time

Figure 9: The receiver state parameters in relation to supplier activities and time [19].

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Figure 10: Part of the realization structure for the RSP called time needed for delivery [19]. Design Procedures The applied case involves improvement design. Four design solutions derived by this improvement design are introduced as we follow each design step explained in the previous chapter. In Step 1, a flow model representing the target service was developed. Here, the warehouse supplier is an initial provider of new forklift trucks, while the warehouse owner is the end receiver and final customer. In the flow model, there is a provider of remanufactured forklift trucks and an intermediate sales function providing the customers with both newly produced. The design team specified the scenario of the warehouse owner using forklift trucks as products (Figure 8). In Step 2, the design team collaborated with the company sales department to develop a customer survey, the results of which were used to identify the RSPs included in the flow model (Figure 8). The design team deployed the RSP cost of warehousing, time needed for delivery, capacity change, and function availability (Figure 9). A time line and supplier company activities are shown in the figure.

In Step 3, the realization structure of the existing service was described. Its feasibility was confirmed in Step 4, in which the supplier activities are related to the RSPs, both shown in Figure 9, and other parameters that need to be included in the realization structure. Figure 10 illustrates part of the realization structure considering the RSP called time needed for delivery. In Step 5, no new RSP was identified. Consequently, in Step 6, there was no need for the placement of a new agent and thus no need to determine the position of a new agent. Furthermore, the realization structures were all verified by the company staff before other design steps were started. During Step 7, the results of the customer survey were used once again. According to the survey, when weighing the importance of the different RSPs through an analytical hierarchy process (AHP) (Figure 11), function availability was found to be most crucial. This result was obtained by inputting the results from the customer survey via the AHP into the realization structures. The design team focused on improving the function availability by considering the RSP view model (realization structure). The analysis clearly showed that the most important functions (including sub-functions) to improve and control

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Figure 11: The analytical hierarchy process list for the RSPs [19].

Bushing

Figure 13: Illustration of a maneuver consol and regulating knobs of a forklift truck [20].

Figure 12: Suspension of an engine in a low-lifting forklift truck [20]. were malfunctions and maintenance, with four FPs: Time needed to detect malfunctions, time needed to send spare parts, time needed to conduct maintenance and frequency of malfunctions) (see Figure 7). Design Solutions Based on the results of Step 7, design solutions were developed to further increase the warehouse owner’s function availability by focusing on, e.g., the reaction time to malfunctions. During the design process, the focus was on how to combine and solve several different problems at the same time. The view model supported this work by providing a structured and validated view of the customer’s validation of different functions. In developing design solutions, the focus was on the need and function. a. Active monitoring Built-in monitoring devices that enable more intelligent pre-identification of upcoming service needs enable preventive service before a breakdown that may require costly service. Active monitoring also facilitates predicting the component requirements, working hours, and when they will be needed. This device can be compared to the kind of device that

is used in cars to alert the driver when it is time for service. To obtain this design solution, we referred to and applied function prototypes derived from past car monitoring service systems. Often, these devices trigger based on miles driven or time since last service. In the case of the forklift truck, the device needs to be more advanced. b. Parts selection based on a broader life-cycle perspective One problem is whether to have plastic or metallic bushings on the motor suspensions (Figure 12). BT has recently changed from metallic to plastic bushings in some of its forklift trucks. In theory, these new plastic bushings are maintenance-free due to lubrication; however, when the forklifts are painted, the grease is dried out and not replaced. During use, the bushings collect dirt, and thus the lifetime of the bushings is shortened. From a broader life-cycle perspective, metallic bushings are preferable since they allow easier and better maintenance. The lifetime of the forklift truck depends greatly on how much and in what working environment it is being used. The problem of plastic bushings is therefore more critical for forklift trucks that are operated many hours a day in dirty environments, e.g., those used in fish-processing industries.

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Figure 15: Improper angle of insertion and position of electronic sockets that facilitates dirt and water collection without any zones of drainage [20].

Figure 14: Current access to the engine [20]. c. Easy access of service Components that tend to need frequent service ought to be easy to access. Accessing the parts inside the maneuver consol of a forklift truck can be tricky. The consol (Figure 13) is attached with 11 screws, all of which are inserted from below. The use of all these screws when assembling and disassembling the consol is both redundant and time consuming. When service is performed on the consol, it takes an unnecessarily long time to disassemble and reassemble the consol, especially if a single person does it. One solution is to replace the screws with durable snap-fits. If necessary, to further secure the parts, screws can still be used. When nondestructive snap-fits are used, the number of screws can be reduced and disassembly and reassembly facilitated, which will reduce the time needed for assembly, maintenance, and remanufacturing if the parts of the maneuver consol or its interior parts need to be accessed. In addition, the plastic covers of the knobs regulating the forklift truck are attached to the maneuver consol with 10 screws, which can be replaced with durable snap-fits. To access the engine of the forklift truck, one must loosen the screw bolt behind the chair and then turn around the steel cover, which is integrated with the chair (Figure 14). This procedure works well as long as one does not need to access the area behind the engine. For access to any part behind the engine, many parts of the engine must be disassembled, which is extremely time consuming. A solution is to install a service door on the outside, which can be integrated with an existing door that provides access to the battery. Although this solution would allow easier access to the engine, the stability of the forklift truck would decrease as the outer steel construction stabilizes the entire forklift truck.

d. Simplify access to testing points Testing points are used to measure functionality before and after the service. When performing tests, it is important to obtain the correct failure information. If incorrect information is displayed due to short circuits, for example, maintenance may take longer than expected. The next design solution deals with this problem. e. Ensure a robust electrical system - The electronics in a forklift truck are exposed to harsh environments. For example, they are often operated in freezer rooms with temperatures as low as -30 degrees Celsius. When the forklift trucks enter different environments, such as while moving between rooms with different temperatures, the electronic components are exposed to condensation. These issues should be considered when designing forklift trucks so that the water from condensation does not enter the electronic components and generate shorts or similar problems. The electronic sockets are exposed and inserted from above, without any protection (see Figure 15), which allows dirt and condensation to collect. These problems can be solved by covering the electronic sockets or by having them inserted from another direction to prevent the collection of dirt and water. Another way of dealing with condensation is to build in drainage zones. The robustness of the electronics is very important for manufacturing and maintenance since the operations performed are dependent on the error code the forklift truck generates when being tested. These design solutions are described in more detail in [20]. The design solutions described above are independently applicable, but if they are combined, they have an increased total potential impact on function. The active monitoring design solution implies that the warehouse supplier will be able, by combining the solutions, to prevent function failures before they occur. The system will report in advance, e.g., that a

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component is near the end of its life or that a component is not working properly. Based on the report, which may be transmitted via Internet, a solution can be identified with an adequate number of new components and the estimated time for service and exchange. This process refers to a logistical system that supports the rapid delivery of components and assemblies. By applying the above-mentioned combination of solutions, a service planning prognostication program is realized on which component planning is based. Business offer design shifts from a focus on simply the product or service to the design of an offer that satisfies the customer and at the same time reduces costs for the supplier. The use of the proposed method supports the innovative design process by identifying new ways to solve problems and to reduce or even eliminate the time needed to react to malfunctions. DISCUSSION Effectiveness of the Proposed Methods and Tool The proposed Service CAD, which has been implemented as computer software, was proven to support designers effectively in the case study. It should be emphasized that the designers logically generated the four design solutions, especially from the described view model of the most crucial RSP, function availability of the service. Thus, the Service CAD allows designers to derive solutions using service activities and physical products to increase customer value. From the results of the case study, it was confirmed that the service design method proposed in this paper is also applicable to the improved design of an actual service in manufacturing industries. In addition, it was verified that service designers could specify the service structure corresponding to the customer needs by performing customer analysis and conceptual design. Since this design method is based on the concept of function and the function-based design process, it is easy for engineers to adopt. Therefore, this design method can solve the two problems of conventional design defined in “SERVICE DESIGN AND SERVICE CAD.” Advantages of the Proposed Method The advantages of the proposed design method are presented by comparison with traditional product design methods. (1) While the target of traditional product design is the function of a product, the target of the presented service design is the state change of a service receiver. Since the design method adopts the assumption that design specifications can be defined within the design process [21], the state change of a receiver is part of the designed objects, thus enabling service designers to design a more suitable solution for a service receiver. (2) The advantage described in (1) means that the solution space of the service design is broader than that of the conventional product design. Thus, a larger variety of design

solutions are expected. Since the requirement of a service receiver is also the designed object, a service provider can expand the solution space on this design method, which is a further advantage of the service design method. (3) Traditional product design involves specifying sufficient information to produce a physical product. The service design method, on the other hand, includes not only product design activity but also an activity to specify the state change of the end receiver and the agents providing the value to the end receiver; therefore, it is possible to derive a more effective design solution than that derived by the traditional product design method. Possible Improvements of the Proposed Method The following possible improvements for the proposed design method have been identified. (1) In the service design process model, Step 7) has not been explained sufficiently in the case study of a warehouse equipment manufacturer. This step should be verified with an actual service case in addition to the evaluation process, which has been proposed already [18]. In addition, the description method of a function prototype in a realization structure database and an agent in an agent database, as well as a method to extract suitable ones from each database, should be discussed. (2) The description of a receiver’s needs should be refined by introducing persona to represent a virtual user [22]. The details of this method should be clarified. (3) In this paper, a concrete method to create a design solution by a computer was not proposed. The authors have planned the implementation of an integrated reasoning environment to utilize design knowledge from various fields with the abduction reasoning technique [23, 24]. CONCLUSION The concepts of service design, the service modeling method for service design and design aid, and the service design process model have been proposed. The concepts have been verified by application to an actual service case. ACKNOWLEDGMENTS We express our appreciation to Mr. Tatsunori Hara, who collaborated in the case study presented here. This research was partially supported by a Research Fellowship Program by the Alexander von Humboldt Foundation in Germany and by the Ministry of Education, Science, Sports, and Culture through a Grant-in-Aid for Scientific Research (B), 18360079, 2006. We also express our appreciation for the cooperation of BT Industries, Sweden, especially Mr. Jan Munde, vice-president. REFERENCES [1] Tomiyama, T., 1997, “A Manufacturing Paradigm toward the 21st Century,” Integrated Computer Aided Engineering, 4, pp. 159-178.

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