فرآیندهای کنترل پیکربندی سند تسخیر شده در جریان کار

This paper proposes a new method of document version management for workflow management systems (WfMSs). A WfMS is considered an essential element for automation of complex business processes involving many companies, particularly for those in an e-business environment. A core element of such business processes is the documents that flow through the processes. In fact, it can be thought that the execution of a business process is often tantamount to working out a set of formed documents. Therefore, it is very important to have a systematic management of document changes along with the process execution. We propose a version model that can take into account the structure of the underlying process over existing version management techniques. In this model, the components of a document and a process are associated with each other, and this becomes the basis for automatic creation of document versions and automatic configuration of relevant documents for a certain user at a certain stage of the process. A prototype system is implemented, and the potential advantages of the approach are discussed.

A workflow management system (WfMS) is a software system that defines, controls and manages business processes [16]. The WfMS is an essential element for the automation of complex business processes, particularly those in an e-business environment [1], [23], [24] and [30]. Such a process usually involves documents, and in many cases, filling out the documents can be understood as an important part of the process execution. In this paper, we propose a new method of managing document changes and configurations for WfMS. Since document handling is an important part of business processes [17], many WfMSs provide functions for creating, delivering, and storing documents to some extent [15] and [18]. They, however, are limited to the storage services and simple delivery of documents, but do not take into account the underlying process that controls the document flow. Conventional version models [21] maintain the change history with timestamps. Since they have been developed independent of WfMS, they have nothing to do with any process model. To the best of our knowledge, there is yet no approach to document versioning that can take advantage of the underlying business process. Consider, for example, the process model in Fig. 1, which is a part of an insurance application process. While the process is proceeding, the application form will be completed by relevant participants step by step in due order of the process model. In an early activity, i.e., ‘sales men,’ ‘telemarketing,’ or ‘Internet sales,’ the section describing the applicant is filled out. In the following activities, ‘register application’ and ‘check identity & credit,’ additional information, like the applicant’s credit, is added to the form, and any erroneous data in the form can be corrected. After a review at ‘evaluate application,’ a couple of alternative plans are prepared for the applicant. Finally, one alternative is chosen at ‘recommend plan.’Version management is especially important when multiple participants can modify the same part of a document. In the above example, every participant preceding ‘evaluate application’ can alter the application form. Suppose that there is an error in the resulting form. Since a typical WfMS keeps only the latest version, it cannot identify who is responsible for the error. This explains the necessity of managing the change history that a form has undergone. Otherwise, it would be unable to answer a change-related query, like “Who modified what part of the form?”. When activities proceed concurrently, like those involved in the second parallel part of the example process, they can produce alternative documents for the same task. Such parallelism makes the version management more complicated. We propose a new model that can control the versions of documents handled by a WfMS. In this model, the components of a document are associated with the components of the underlying process model. The proposed model is unique in that the versioning takes into account the process semantics, such as the structure, pattern, and definition of processes. This allows the history of the document to be understood in the light of the process’ progress, so that it enables users to check immediately the status of the document at a certain step of the process, and to compare the contents before and after the change. The proposed function is especially important in e-business environments in which many companies exchange documents. Our model facilitates tracing the change history of a document along the flow of a process. It can also be used as a basic mechanism for workflow recovery that restores a process status back to a previous one when some exceptions take place.

The main purpose of our research is to develop a method of managing changes of documents in workflow processes. To overcome conventional WfMS’ limitations, namely that they deal with only the latest versions of documents, we propose a new model for versioning and configuring workflow documents. The essence of the proposed approach is that it takes into account the semantics of the underlying process. We propose a build-time model that modularizes a document into multiple parts and each of the parts is associated with the activities of the underlying process. We also propose a run-time model for document check-in and check-out, with which the management of document versions is automated. Our approach provides several advantages. First, it helps workflow users with automatically checking out the right document version that the users have to work with. Second, users can have a better understanding of document changes. This is because the document changes are tightly associated with the underlying workflow processes, and our system can visualize it. Third, it is possible to recover a document into an earlier version that has been created before. When the process execution needs to return to a previous activity due to system errors or exceptional cases, it is necessary to recover the right document version for that activity. We think that our version model can be a solution to the issue of workflow recovery. There are several interesting research issues. First, it is important to support various flow patterns, such as those in [3] and [7]. The proposed approach cannot cover all the flow patterns that are found in the real world. For example, a cyclic or loop pattern is used when a set of activities need to be repeated. For a simple cycle, the proposed approach can be applied by unfolding the repeated portion as many times as the number of repetitions. However, when the cycle is allowed to combine itself with other flow patterns, it is not an easy task to deal with the proliferation of flow patterns. Another issue is to develop standardized APIs or a standard versioning protocol for version management to interface with different WfMSs. APIs in product data management enablers and open document management APIs provide functions related to managing document, but they do not support version management in the context of process flow. Still, an interesting issue is to support cooperative authoring in computer supported collaborative work environments [32]. A cooperative authoring process involves multiple authors and thus many changes may take place even at the same time.