Workflow Design 工作流设计

Toward Workflow Block Activity Patterns for Reuse in

Workflow Design

Lucinéia Heloisa Thom and Cirano Iochpe

Federal University of Rio Grande do Sul, Brazil;

Vinícius Amaral and Daniel Viero, iProcess, Brazil

1.I NTRODUCTION

Research on both business process modeling and implementation issues re-lated to workflow technology have quickly increased over the last years. The most significant initiatives are in the field of standardization [1], [2], [4], specification [5] and workflow definition languages [6], [7], [3]. However, since it is a relatively new and still evolving technology, workflow design pre-sents some challenges, especially with respect to techniques that can en-force correctness as well as efficiency during both the requirements analysis and the modeling phase of the workflow project.

Within this context, research on workflow patterns has attracted increasing attention mainly because of the advantages of reusing patterns [8], [9]. The most extensively studied are in the field of control/data flow patterns [10], [11] as well as resource and application–oriented patterns (12). Such pat-terns are being used not only in business/workflow process modeling but also in critical evaluations of workflow languages and workflow tools (13). However, a lot less research can be found relating workflow design to a set of recurrent business process “pieces” or “parts” that must be atomically exe-cuted by the workflow process (e.g., an activity request execution and a noti-fication activity). Although one can precisely characterize the semantics of such business process “pieces” [14], [15], [16] and they have to be recur-rently re-designed in practically every workflow modeling process, there is no known research relating these business process structures to workflow pat-terns.

1.1 Approach

Our approach applies the concept of block activity to well-known business processes. An activity set is a self-contained set of activities and transitions [7]. Transitions in the set should refer only to activities in the same set and there should be no transitions into or out of the set. Activity sets can be modeled as block activities. The block execution starts at the first activity in the set and executes the next activities by following the partial order im-posed upon them by the transitions until an exit activity is reached. Work-flow execution then returns to the next activity following the block.

In this paper, we apply the block activity concept in order to represent a set of business (sub-)process types (e.g., logistic, financial, information and de-cision) that we call “workflow block activity patterns”. These patterns are re-lated to a set of specific atomic structures that are frequently found in busi-ness processes and have already been identified in the literature [14], [15],