COMPUTER INTEGRATED MANUFACTURING:CIM IMPLEMENTATION

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CIM IMPLEMENTATION

CIM implementation is a very important but also very complex process. It requires the participation of many people with different disciplines. Benefits can be gained from successful implementation, but loss of investment can be caused by inadequate implementation. Therefore, much attention should be paid to CIM implementation.

General Steps for CIM Implementation

The general life-cycle model discussed in CIM architecture and modeling methodology is the overall theoretical background for CIM implementation. In a practical application, due to the complexity of CIM implementation, several phases are generally followed in order to derive the best effect and economic benefits from CIM implementation. The phases are feasibility study, overall system design, detailed system design, implementation, operation, and maintenance. Each phase has its own goals and can be divided into several steps.

Feasibility Study

The major tasks of the feasibility study are to understand the strategic objectives, figure out the internal and external environment, define the overall goals and major functions of a CIM system, and analyze the feasibility of CIM implementation from technical, economical, and social factors. The aim of this phase is to produce a feasibility study report that will include, besides the above, an investment plan, a development plan, and a cost–benefit analysis. An organization adjustment pro- posal should also be suggested. A supervisory committee will evaluate the feasibility study report. When it is approved, it will lay the foundation for following up the phases of CIM implementation. Figure 27 presents the working steps for the feasibility study.

Overall System Design

Based on the results of the feasibility study, the overall system design phase further details the objectives and plans regarding proposed CIM system implementation. The tasks of overall system design are to define the CIM system requirements, set up the system function and information model, put forward an overall system design plan, design the system architecture, draft the implementation plan, present the investment plan, carry out the cost–benefit analysis, and finally form the overall system design report. The key technologies and their problem-solving methods should also been given in the overall system design report. Data coding is important work to be done in the overall system design phase.

In order to keep the whole CIM system integrated, in the functional and logical model design, the overall system design follows the top-down decomposition principle. The top level and general functions should be first considered, then decomposed to low-level and detailed operations.

The general procedures and contents of overall system design are as follows:

1. System requirement analysis: determines the system requirements of function, performance, information, resource, and organization. This phase’s work focuses on the managerial and tactical point of view.

2. System architecture design: determines the overall system architecture of the CIM system.

3. System function and technical performance design: determines the functions needed to meet the system requirements and system performance.

4. Information model design: determines the logical data model of the information system.

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5. Internal and external interface design: determines these interfaces for the purpose of system integration, including the functional interfaces between different subsystems and data inter- faces between different applications.

6. Key technology: lists all key technologies that have important influence on CIM system im- plementation, gives their solution methods;

7. System configuration specification: determines the hardware and software configurations.

8. Implementation schedule definition: defines the implementation schedule for the CIM system in the network plan or other forms.

9. CIM system organization definition: defines the suitable organization structure for the CIM environment.

10. Budget making and cost–benefit analysis.

11. Overall system design report generation.

Detailed System Design

The detailed system design phase solves the problem of system specification definition, the associated hardware and software configuration assignment, the functional and data interface definition, the implementation plan and making of steps, the forming of the associated implementation team, and the assignment of responsibility and setting of benchmarks.

In this phase, an important goal is to define the interfaces between different subsystems. The shared data physical model for the CIM system needs to be specified. The number, type, and con- figuration of hardware systems should be defined. The detailed software products that should meet the requirements defined in overall system design should also be specified. The network scheduling for the implementation plan should be generated and evaluated. A leadership group is formed that will manage the entire CIM implementation. A number of implementation teams with personnel from different disciplines and different business sectors are formed. Each implementation team will be engaged in the implementation of a specific part of the CIM system.

After the detailed system design phase is finished, the CIM system is ready to go into practical implementation.

Implementation and Operation

The implementation phase follows a bottom-up approach. Subsystems are implemented in order according to the implementation scheduling. When the subsystem implementation is finished, inte- gration interfaces between the subsystems are developed and several higher-level subsystems are formed through integration of some low-level subsystems. Finally, the whole CIM system is imple- mented through an integration.

After the system is built and tested, it becomes an experimental operation, which will last for three to six months. During that period, errors that occur in the operation are recorded and system modifications are carried out. The CIM system is turned to practical use. In the implementation and operation phase, the following steps are generally followed:

1. Building computer supporting environment: including computer network, computer room, net- work and database server, UPS, air conditioner, and fire-proof system

2. Building manufacturing environment: including whole system layout setup, installation of new manufacturing devices, and old manufacturing configuration

3. Application system development: including new commercial software installment, new appli- cation system development, old software system modification

4. Subsystem integration: including interface development, subsystem integration, and system operation test

5. CIM system integration: including integration and testing of whole CIM system

6. Software documentation: including user manual writing, operation rule definition, setting up of system security and data backup strategies

7. Organization adjustment: including business process operation mode, organization structure, and operation responsibility adjustment

8. Training: including personal training at different levels, from top managers to machine oper- ators

9. System operations and maintenance: including daily operations of CIM system, recording of errors occurring in the operation, application system modification, and recording of new re- quirements for future development

Integration Platform Technology

Requirements for Integration Platform

The complexity of manufacturing systems and the lack of effective integration mechanisms are the main difficulties for CIMS implementation. Problems include lack of openness and flexibility, incon- venient and inefficient interaction between applications, difficulty in integrating a legacy information system, the long time required for CIMS implementation, and the inconsistency of user interfaces.

To meet the requirements enumerated above, the integration platform (IP) concept has been pro- posed. IP is a complete set of support tools for rapid application system development and application integration in order to reduce the complexity of CIMS implementation and improve integration ef- ficiency. By providing common services for application interaction and data access, IP fills the gaps between the different kinds of hardware platforms, operating systems, and data storage mechanisms. It also provides a unified integration interface that enables quick and efficient integration of different applications in various computing environments.

The Evolution of Integration Platform Technology

IP has evolved through a number of stages. It was initially considered an application programming support platform that provided a common set of services for application integration through API. A typical structure of the early IPs is the system enabler / application enabler architecture proposed by IBM, shown in Figure 28. Under such a structure, the IP provides a common, low-level set of services for the communication and data transfer (the system enabler) and also provides application domain specific enabling services (the application enabler) for the development of application systems. Thus, the application developer need not start from coding with the operating system primitive services. One disadvantage of the early IP products was that they only provided support for one or a limited number of hardware and operating system and the problem of heterogeneous and distributed com- putation was not addressed. Also, the released products often covered a specific domain in the enterprises, such as the shop-floor control. These early IPs focused mainly on support for the devel- opment of application software, and their support for application integration was rather weak.

Since the 1990s, IP has developed for use in a heterogeneous and distributed environment. An example is shown in Figure 29, where the architecture is divided into several layers, the communi- cation layer, the information management service layer, and the function service layer

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commonly used system-level services. These services form the middleware layer of IP. The higher layers of IP are classified as general-purpose API, domain-specific API, and application development integration tools. The integration supporting area is extended from a specific domain to the whole enterprise, including management, planning, and manufacturing execution.

MACIP System Architecture

MACIP (CIMS Application Integration Platform for Manufacturing Enterprises) is a Chinese national high-technology R&D key technology research project. The MACIP project is designed to develop a research prototype of an application platform oriented to the new IP technology described above.

The MACIP system architecture is presented in Figure 30. It is a client–server structured, object- oriented platform with a high degree of flexibility. MACIP consists of two layers, the system enabling level and the application enabling level. The system enabling level is composed of two functions, the communication system and the global information system (GIS). The primary function of these components is to allow for the integration of applications in a heterogeneous and distributed com- puting environment. The communication system provides a set of services that allow transparent communication between applications. The global information system allows applications to have a common means for accessing data sources in a variety of databases and file systems. These functions are implemented in the form of application independent API (AI API). Application independence means that these functions are not designed for specific applications but are general services for communication, data access, and file management. Hence, the system enabling level provides the basic integration mechanisms for information and application integration.

The application enabling level, which utilizes the functions contained within the system enabling level, is composed of three domain sub-integration platforms (SIPs): MIS SIP, CAD / CAM / CAPP SIP, and shop-floor control SIP. Each SIP is designed according to the requirements of a domain application and provides functions for applications in the form of Application Dependent API (AD API). The AD API functions are designed specifically to enable the quick and easy development of

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domain specific applications. These functions enable the complete integration of the application. Application development tools (APD tools) are developed using the AD-API. Users can also develop applications using the functions provided by AD-API. Existing applications are integrated by modi- fying the data exchange interface using AD-API functions. An Internet interface is also included in the application enabling level interfaces and provides access to MACIP through appropriate Internet technologies.

An operation management system was also designed that uses AI API functions to provide an application management API (AM API) for the users. Users use AM API to develop management applications that manage the IP resources and coordinate the operation of different applications.

The development of MACIP was finished in early 1999. It has since been used in several com- panies to support the rapid implementation of CIMS.

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