Business Modelling


introduction model software example hypermedia conclusions references appendix
Dramatic improvements in business performance and productivity may be achieved by critically examining some of the rules that govern a business process. Business Process Redesign (BPR) is the generic label for many emerging methodologies aimed at producing these improvements. Re-design implies that the current state of affairs is no longer acceptable and can no longer be refined or evolved. The BPR perspective demands that its users understand the nature of the business they are in, and the processes that can be re-engineered. In order to achieve this understanding, part of the BPR approach is to map out an organisations processes. The model created during this phase is used to communicate the BPR team's ideas and will also be used to plan changes to the current processes. Following Davenport and Short  [Davenport90] we define a business process as "a set of logically related tasks performed to achieve some well-defined business outcome". It is important to note that business processes have customers that, somehow, receive the outcome of these processes. Also, to stress the functional nature of business processes, it may be remarked that business processes often transgress departmental boundaries within an organization.

Despite the importance of qualitative assessments in BPR  [Hammer90], for modelling we favor a more quantitative approach for which we provide support by means of a simulation library (BPSIM) based on the Logistics-based Business Modelling method (LBM) presented in  [Gerrits95].

Logistics-based modelling allows for analysing the time spent in executing a business process. The product lead time is defined as the time that passes between the moment a customer orders a product and the moment a product is delivered. In more detail, we can distinguish between processing time (the time actually worked on a job or operation), queue time (the time a jobs waits for a resource to become available), setup time (the time that passes between the moment a resource becomes available and the moment work on the job is started), wait time (the time that is spent waiting for another job to complete), and transport time (the time that is needed to move a job from a resource at a certain location to a resource at another location).

For a particular model, measurements may be obtained by running a series of simulations. Based on an analysis of the simulation results alternative models may be proposed. For example, when the setup time for a job is relatively large, combining jobs into a single task for an employee may be more efficient.

Modelling Business Processes

The LBM method offers a number of primitives, with associated graphic icons, from which a business process model may be constructed as a network of resources connected by transport arcs. The primitive entities offered by LBM are: Operations are atomic in the sense that wait time, queue time and transport time may not be part of an operation. Only setup time and process time are part of an operation. Tasks are introduced to allow for a series of jobs or operations to be processed, for example by one employee, in order to reduce the setup time needed. Transport entities represent the time it takes for information to flow from one resource (that is operation or task) to another. Transport implicitly defines the sequential structure of a process. However, duplications of information, and consequently parallel operations, are allowed.

In addition to the primitives mentioned above, LBM allows us to characterize

Also, employees may need additional means to engage in an operation or task.
introduction model software example hypermedia conclusions references appendix