Transcription

Workflow management: enablingprocess integration in productionmanagement k3)M Rosemann J) ,Chr. von Uthmann2) ,D. Frzn1) Queensland University of TechnologySchool ofInformation Systems2 George Street, GPO Box 2434, Brisbane Q 4001, AustraliaTel: 61 7 3864 1125, Fax: 61 7 3864 1969e-mail: [email protected])University ofMuenster, Department ofInformation SystemsSteinfurter Str. 107, 48149 Munster, GermanyTel: 49 (0)251/83 38064, Fax: 49 (0)251/83 38 109e-mal: [email protected])Research Institutefor Operations Management at University ofTechnology, Pontdriesch 14116, 52062 Aachen, GermanyTel: 49 (0)241147705-42, Fax: 49 (0)2411402401e-mail: [email protected]deAbstractSo far workflow management as an organizational and technical approach tointegrate business processes has mainly been discussed in the area of officemanagement and in service industries like banks or insurance companies. Thispaper describes the general characteristic of processes that are appropriate forworkflow-support. Processes with these characteristics can be identified within themain areas of production management, namely construction, production planningand control and quality management. Finally, this paper ends up suggesting twodifferent approaches for possible workflow-based PPC-architectures.KeywordsProcess management, workflow model, construction, production planning andcontrol, quality managementK. Mertins et al. (eds.), Global Production Management Springer Science Business Media New York 1999

3761Workflow management: Enabling processOBJECTIVEWhile the term computer integrated manufacturing (CIM) has been loosingpopularity rapidly, data, function and process integration as the main objectives ofthis philosophy are still of high relevance to a realization of efficient productionmanagement systems. In the past, it has been dealt intensively with data integrationand integrated database management systems can be found in nearly everycompany. In contrast to this, the industrial sector is scarcely paying attention toprocess integration. Since the beginning of this decade the focus on integrationefforts is shifting towards process management. In this context, process orientationis discussed under organizational concepts like Lean Production, Just in Time,Total Quality Management, Supply Chain Management, EN IS0900x or BusinessProcess Reengineering. Integrated information systems do not only have to provideapplications and data for supporting single activities of business processes but alsoneed to support the process control for the coordination of logical dependentactivities.Similar to database management systems that support the integration of data,workflow management systems (Jablonski, Bussler 1996; Kobielus, 1997) havebeen developed to support the integration of functions within business processes.Although these workflow management systems have meanwhile reached a highdegree of functionality and stability and are intensively used in service industrieslike banks or insurance companies they have been considered in productionmanagement only to a minor extent.This paper contributes to a placement of the term and the concept of workflowmanagement into the context of production management systems. By taking theintegration dimensions of the computer integrated manufacturing approach, thecharacteristics and the intention of workflow management systems are marked off.Thereafter, it will be analyzed which processes in production management areappropriate for workflow support and which are the main benefits of usingworkflow management as support for these processes. The potential of workflowmanagement will be ascertained for the key processes in manufacturing systems:construction, production planning and control, and quality management. Finally,two possible approaches for a workflow-based architecture for PPC-systems willbe differentiated.2CHARACTERISTICS OF WORKFLOW MANAGEMENTWorkflow management is a discipline of office management and computersupported cooperative work (CSCW) (Dix, 1994). It can be defmed as themodeling, execution and control of business processes. Workflows are processeswith automated transitions between the embedded activities. The transitions fromactivities to their succeeding activities are controlled by an information system, theworkflow management system. Workflow models are usually described as directedgraphs whose nodes represent elementary or composite functions (Jablonski,

Workflow management: Enabling process377Bussler, 1996; Weske, Vossen, 1998). In addition to a model for a businessprocess, a workflow model has to consist of (Rosemann, 1998; Rosemann, zurMiihlen, 1998)input and output data for every function;precise descriptions at the splitting and joining nodes;organizational responsibilities for every function, usually depicted as roles;specification of the invoked applications (location, parameters).Workflow management systems are characteristically designed as middleware.They separate the process control from application systems. Consequently - fromthe viewpoint of a workflow management system - the functions within a processare black-boxes. One central function of workflow management, which is theautomated coupling of single activities targets the decrease of transfer errors,transport time and idle time, as well as the reduction of routine work foremployees, the support of parallel processing and a just-in-time informationtransfer. The second central function is the assignment of work items to workflowparticipants via a worklist. These assignments are proceeded during the runtime ofa workflow according to qualification and organizational properties specified asroles. The notification, synchronization and handling of worklists support theefficient cooperation of workflow participants with regard to the completion of thework items within workflows. A further important aspect of workflowmanagement is workflow monitoring which enables partially automatedsupervision of workflows within control circuits. For this purpose, the workflowlog files (audit trail) can be converted, aggregated and used within a processinformation system that includes different statistical methods (clustering) or earlywarning functions in order to support the process owner.Processes which can be supported by workflow management systems have thefollowing characteristics:The processes are at least partially pre-structured, i. e. processes can bedescribed in advance through process models. Processes which can only bedetermined during runtime - so-called ad-hoc-processes - will rather besupported by groupware systems.Due to restrictions of the economic efficiency of modeling and executionactivities, the processes to be supported with workflow management systemsshould be executed with a certainfrequency within a period.The processes are performed by several workflow participants resp. severalapplication systems working together asynchronously.Only in these cases it is worthwhile to profit from the coordinative functionality ofworkflow management systems. In addition to these main prerequisites, furthertechnical, organizational and economical criteria have to be taken into account inorder to identify the most appropriate processes for workflow support (Becker etaI., 1999).Processes with these characteristics can principally be found in manufacturingsystems (Rosemann, von Uthmann, 1997; Rosemann, von Uthmann, 1999). Incontrast to purely administrative processes, a special property of productionprocesses is their correspondence to material flows whose control implies special

378Workflow management: Enabling processrequirements for information systems. Moreover, processes in manufacturingsystems tend to be complex through the involvement of many departments (see theconstruction process as an example). Furthermore, the heterogeneous systemenvironment consisting of administrative applications like PPC-software and moretechnical components like computer aided engineering/design/manufacturingrequires to manage various interfaces and the handling of different coexisting dataformats. Hence, in comparison to the purely administrative sector, processes inmanufacturing systems are characterized by complex organizational andtechnological conditions which impede the utilization of workflow management.Having this in mind, in the following chapter the potential of workflowmanagement systems is analyzed for the essential industrial processes in the areasof construction, production planning and control, and quality management.3POSSIBLE WORKFLOWS IN PRODUCTION MANAGEMENTIn construction, there is a high demand for structuring and representing processesin a more transparent way, as well as for a goal-directed use, re-use andmodification of existing information. Though organizational principles and actionguidelines have been set up, the essential precondition for typical workflowmanagement systems is hardly being considered. An appropriate workflowmanagement solution for the support of construction processes has to be flexiblyadaptable to the individual product requirements and unforeseen situations withinrunning processes. A proposal for a solution of this problem is the concept ofworkflow-based business process control (von Uthmann, 1998). It is based on thecreation of model components referring to work items which can be assembledaccording to individual products and specific situations. Workflows in this areahave to handle complex product data as well as administrative data like materialmaster data or bill-of-materials. Besides the general advantages of workflowmanagement, the main benefit of using this middleware for the execution ofengineering processes is the standardization of these processes that are usually notplanned. Data gained by workflow monitoring can be used to better calculate theengineering time and leads to a more realistic estimation for the entire orderprocessing time and the prize calculation. In most cases, the critical time-to-marketcan be reduced significantly.As far as the use of workflow management for production planning and control(PPC}-processes is concerned it can be stated that the control systemsimplemented within the last thirty years do already perform large parts of thefunctions. Nevertheless, the existing solutions mainly support PPC-functionsindividually and do not take a holistic process perspective into account.Furthermore, they are often limited to a process logic that is conform with theMRP II (Manufacturing Resource Planning) framework and that supports only thepure PPC-processes without sufficiently integrating administrative functions likeaccounting or human resource management. As a consequence, several potentials

Worliflow management: Enabling process379for the use of workflow management can be identified, which can increase thedegree of process orientation within PPC-systems.One principle of quality management is to secure a managed level of quality bycontrolling processes within integrated process control circuits. In this context, thepotential of workflow management is presented in the basic model of workflowbased business process modeling which describes the structure of a cascadingcontrol in three circuits with workflow management as key component of truevalue generation and regulation (von Uthmann, 1998). The automation of functiontransitions contributes to the improvement of process control by minimizing errorscaused by manual influences. At the same time the implementation of workflowbased control circuit systems together with an increasing employees' involvementcan help to identify and compensate quality defects during the processing ofworkflows. Parallel to the execution, audit trails can be automatically created as acomprehensive process audit. These data can be aggregated and presented byprocess information systems (PIS). Such a system would enable to identify criticaltrends concerning the process performance immediately and to trigger appropriatecompensation mechanism. Moreover, the process models created during workflowspecification can be used for the documentation of processes necessary for acertification following standards like the EN ISO 900x.4TWO ARCHITECTURES FOR A WORKFLOW -BASED PPCFocussing on production planning and control, this chapter explains two possiblearchitectures for a workflow-based PPC. The two architectures can bedifferentiated by their requirements concerning the necessary modification of thePPC-system.The first architecture is characterized by the fact, that it requires only relativeminor changes of the existing PPC-system. It increases the degree of processorientation as it integrates the single PPC-functions along processes.Characteristically, in this workflow-integrating architecture the workflowmanagement system is an additional system on top of the PPC-system. On thesame level of abstraction, this approach aims to integrate related applications in thearea of fmancial accounting, cost and revenue controlling, asset management, orhuman resource management. Consequently, such an approach is interesting forcompanies that are planning to exchange their PPC-system in a few years and arenot willing to invest heavily in their current PPC-system. Nevertheless, thisarchitecture streamlines the use of the PPC-system and reduces problems at theinterfaces between the PPC-system and other related applications. In this case, theworkflow-based processes still follow the concept of MRP II.An example for a workflow fitting to this scenario is the process of invoiceverification, which integrates functionality belonging to material management inthe first part of the process with the accounts payable module of fmancialaccounting in the second half of the process. Figure 1 shows the general principleof this architecture. Existing functions in a PPC-system are re-grouped in a process

380Workflow management: Enabling processthat is executed by a workflow management system. The granularity of theembedded functions is the same as in the PPC-system without a workflowmanagement system.PPC-SystemWorkflow ManagementProcessesFunctionsFigure 1 Workflow-integrating PPC-architectureIn addition to the objectives of the first architecture, the second suggestion is farmore innovative as it changes the granularity of the embedded PPC-functions tomake alternative logical sequences of activities possible. The main motivation is toenable processes that are different to typical MRP II processes. An example for thisare the requirements of the furniture industry: In this branch, the results oftransportation planning are input data for the capacity management. Finally,material management has to calculate the demand for material and products.Besides industry-specific requirements, the demand for alternative PPC-processescan also result from PPC-philosophies like the Optimized Production Technology(OPT) (Goldratt, 1988) approach, that starts with the identification of typicalbottlenecks followed by capacity management for the other machines, lot sizeoptimization and material management. In order to realize these kind of processes,it is indispensable to restructure the functions of a PPC-system. In comparison witharchitecture 1, the functions must be of a fmer granularity. An efficient executionof these processes still depends on the support from workflow managementsystems, which is in this case an embedded module of the PPC-system (workflowbased architecture).As a consequence, such an architecture is of relevance to manufacturingcompanies with individual requirements concerning the desired sequence ofactivities. Furthermore, they should use a PPC-system that is easy to divide in submodules. Ideally, the architecture of the PPC-system follows the principles ofobject orientation. Figure 2 stresses the main idea underlying this architecture.

Workflow management: Enabling edFunctionsFigure 2 Workflow-based PPC-architectureCurrently, the University of Miinster, Department of Information Systems, theResearch Institute for Operations Management (FIR) at Aachen University ofTechnology, four manufacturing companies, a workflow provider and a softwarecompany providing a PPC-solution are working together in the research project"PROWORK - prodcution planning and control with workflow managementsystems for a more efficient order processing" on a reference model for aworkflow-based PPC-architecture. The aim is to put the two architecturesdescribed above in concrete terms and to develop a generic procedure model forthe introduction of workflow management into the area of production planning andcontrol. Actually, we are consolidating existing reference models and identifyingprocesses that could be realized as workflows. It is planned to implement selectedworkflows in the PPC-domain at the participating manufacturing companies inorder to get an empirical evidence for the research results (see also von Uthmann,Stolp, Meyer, 1997).5REFERENCESBecker, J., von Uthmann, Chr., zur Miihlen, M. and Rosemann, M. (1999)Identifying the Workflow Potential of Business Processes, in Proceedings ofthe Hawaii International Conference on System Sciences (HICCS).Dix, A. (1994) Computer Supported Cooperative Work: A Framework, in DesignIssues in CSCW (eds. D. Rosenberg, Chr. Hutchison), London et aI., 9-26.Goldratt, E. M. (1988) Computerized shop floor scheduling, in InternationalJournal of Production Research, 3, 443-455.Kobie1us, J.G. (1997) Workflow Strategies, Foster City, CA, et al.

382Workflow management: Enabling processJablonski, 8t. and Bussler, Chr. (1996) Workflow Management. ModelingConcepts, Architecture and Implementation. London et ai.Rosemann, M. (1998) Managing the Complexity of Multiperspective InformationModels Using the Guidelines of Modeling, in Proceedings of the 3rrl AustralianConference on Requirements Engineering (eds. D. Fowler, L. Dawson),Geelong, 101-118.Rosemann, M. and zur Miihlen, M. (1998) Evaluation of Workflow ManagementSystems - A Meta Model Approach. Australian Journal of InformationSystems, 1, 103-116.Rosemann, M. and von Uthmann, Chr. (1997) Workflow Management inManufacturing (Workflowmanagement in der industriellen Produktion). ZWFZeitschriftjUr wirtschaftlichen Fabrikbetrieb, 7-8,351-354.Rosemann, M. and von Uthmann, Chr. (1999) Workflow Management as aFoundation for a Process-oriented PPC (Workflowmanagement als Basis einerproze13orientierten PPS). PPS Management, 1,27-31.von Uthmann, Chr. (1998) Workflow-based Business Process Control: AnApproach to Improve the Management of Concurrent Engineering, inProceedings of the 5'h ISPE International Conference on ConcurrentEngineering - CE '98 (eds. S. Fukuda, P.K. Chawdhry), Tokyo, Japan, 223227.von Uthmann, Chr., Stolp, P. and Meyer, G. (1997) Workflow Management inIntegrated Applications: A Report about the Workflow-Project at the ABBTurbinen Niimberg GmbH. (Workflowmanagement in integriertenAnwendungssystemen: Ein Bericht iiber das Workflow-Projekt der ABBTurbinen Niirnberg GmbH), in HMD- Theorie und Praxis derWirtschaftsinformatik, 198, 107-114.Weske, M. and Vossen, G.: Workflow Languages (1998), in Handbook onArchitectures of Information Systems (eds. P. Bemus, K. Mertins, G. Schmidt),Berlin et aI., 359-379.6BIOGRAPHYMichael Rosemann, Dr. rer. pol., Dipl-Kfm., born 1967, studied BusinessAdministration at the University of Miinster. He worked for the Department ofInformation Systems, Miinster, from 1992-1999. He received his Ph. D. inInformation Systems in 1995. His dissertation dealt with complexity managementin process models. Since 1. August 1999 he is Senior Lecturer at the QueenslandUniversity of Technology, Brisbane, Australia. His main areas of research areproduction planning and control, logistics, enterprise resource management,information modeling, and workflow management. Together with Prof. Dr. JorgBecker he is leading the project "Controlling and monitoring of distributedworkflows for a continuous optimization of business processes". This project isfunded by the German Research Society.

Worliflow management: Enabling process383Christoph von Uthmann, Dipl-Wirt. Ing., born 1967, studied BusinessEngineering at the University of Padcrbom. He is working for the Department ofInformation Systems, Munster, since 1996. His main areas of research areproduction planning and control, concurrent engineering, simulation, informationmodeling, and workflow management. He consulted a manufacturer with theimplementation of a workflow management system. Christoph von Uthmann is amember of the research project PROWORK. - production planning and control withworkflow management systems for a more efficient order processing", whichtargets to develop architectures fo a workflow-based PPC.David Frink, Dipl.-Kfm., born 1972, studied Business Administration at AachenUniversity of Technology after fmishing a two-year-practical training at a majorGerman bank. He is working for the Research Institute for OperationsManagement, Department of Production Management, Aachen, since 1996. Hisfocus of research are the areas of production planning and control, technical orderprocessing, information modeling, and engineering data management. Heconsulted various enterprises with the selection and implementation of PPC andERP systems. David Frink is a member of the research project "PROWORK. production planning and control with workflow management systems for a moreefficient order processing", which targets to develop architectures for a workflowbasedPPC.

minor changes of the existing PPC-system. It increases the degree of process orientation as it integrates the single PPC-functions along processes. Characteristically, in this workflow-integrating architecture the workflow management system is an additional system on top of the PPC-system. On the