1 / 11

Process Modeling

Process Modeling. Fundamentals. Three Ways to Understand a System. By its processes What are the systems main processes? By its data What data does the system maintain? By its output What output will the system produce? All 3 should be consistent with each other.

merrill-bryan
Download Presentation

Process Modeling

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Process Modeling Fundamentals

  2. Three Ways to Understand a System • By its processes • What are the systems main processes? • By its data • What data does the system maintain? • By its output • What output will the system produce? All 3 should be consistent with each other.

  3. When is Process Modeling done? Process Modeling is part of the requirements Structuring Stage. We create process, logic and data models based on information gathered during the Requirements Determination stage (through interviews, surveys, etc.). In this way, requirements structuring helps guide us through determination, e.g. knowing what questions to ask in interviews.

  4. Learning Objectives • How to model organizational processes and the data they use, store and produce • Understand rules and guidelines for drawing data flow diagrams • How to decompose data flow diagrams into lower-level diagrams • Rules of balancing data flow diagrams

  5. Learning Objectives • Explain the differences among four types of DFDs: current physical, current logical, new physical and new logical • Discuss the use of data flow diagrams as analysis tools

  6. What is Process Modeling? • A way to graphically represent the system under study as processes that capture, manipulate, store and distribute data between a system and its environment and among system components • There are many techniques that can be used for modeling processes • Structured analysis and design models processes with data flow diagrams (DFDs) • Data flow diagrams are a way to graphically illustrate movement of data between external entities outside the system and the processes and data stores within a system

  7. Process Modeling • Some deliverables and outcomes for current and proposed system • Context data flow diagram • Logical DFDs • Level 0, level 1’s, etc. • Technology independent • Show data flows, structure and functional requirements of system • Processing logic • Project dictionary and CASE repository

  8. Four Types of Process Models

  9. Guidelines for Drawing DFDs • Completeness • DFD must include all components necessary for system • Each component must be fully described in the project dictionary or CASE repository • Consistency • The extent to which information contained on one level of a set of nested DFDs is also included on other levels 8.9

  10. Guidelines for Drawing DFDs • Timing • Time is not represented well on DFDs • Best to draw DFDs as if the system has never started and will never stop. • Iterative Development • Analyst should expect to redraw diagram several times before reaching the closest approximation to the system being modeled 8.10

  11. Guidelines for Drawing DFDs • Primitive DFDs • Lowest logical level of decomposition • Decision has to be made when to stop decomposition 8.11

More Related