Process Modeling with Data Flow Diagrams (DFD)

1. Process ModelingwithData Flow Diagrams (DFD) Introduction

2. What is a Business Process? • A network of activities, resources, facilities, and information that interacts to achieve some business function1 1 Inventory Mgmt Process, Experiencing MIS, Kroenke, Pearson Prentice Hall, 2008, Chpt 2

3. Why Model a Business Process? • Description / Explanation (e.g. to a new hire you are training) • Prescription (e.g. to your boss for how it can be improved)

4. Sample Graphical Tools for Modeling Organizations • PEOPLE: Organization Chart (a.k.a. "Org Chart") • hierarchal people model • shows who reports to whom • DATA: Entity Relationship Diagram (a.k.a. "ERD"): • data only model • no people, hardware, flows or processes • PROCESS: Data Flow Diagram (a.k.a. "DFD") • activities, people, hardware, & data model. • the focus for this part of BSAD 141!

5. Terminology for DFD Process Modeling • 2 Types of “Entities”: Person, place, or thing (e.g. computers) • External: any entity that does not perform any information processing activities • Internal: an entity that performs at least one information processing activity • 2 Types of “Activity”: an action being performed by an internal or external entity. • Information processing (DP) actions: • transform data • retrieve data from storage • filing data • document processing • data entry • verification • classification • arrangement or sorting • calculating • summarizing • NOT information processing (NDP) actions: • Sending & receiving data between entities are NOT information processing actions. • Operational & physical business activities are NOT information processing: e.g. picking or packing a sales order, inspecting goods at receiving dock, or counting cash.

6. What is a Data Flow Diagram (DFD) • A graphical representation of a business system or subsystem that shows how system components (entities, activities and data) are interconnected.

7. More DFD Terminology • Business Process • An activity that converts inputsintooutputs • Verbs rather than Nouns • Types: DP vs NDP • Data Flow • Data moving from one place to another without being transformed • a.k.a. pathway for data • Data Store • A data flow at rest • External Entity • An object that either sends or receives flows from within the system (a.k.a. focus area) but doesn’t perform any processing activities of interest • a.k.a. terminator, source, or sink

8. 1.0 1.0 Enter Report Parameters Enter Report Parameters Project Managers Customer Order Customer Order Completed Orders Completed Orders DFD Symbol Sets Yourdon-DeMarco Gane-Sarson • Process • Data Flow • External Entity • Data Store or Customer Customer or or

9. Two Types of DFDs • Context Diagram: • A graphical, top-level (i.e. overview) representation of the data flows into and out of a single system under study. • Marks the “boundary” (scope) of the sub-system under study (a.k.a. focus area). • Often exploded into more detail. • Context Example: • Logical or Physical Data Flow Diagram: • A detailed graphical representation of the data flows, processes, stores, and sources/destinations in a business sub-system. • Used to model: • How “processes” transform input data flows into output data flows • How “data” move through an information system • Logical DFD Example / Physical DFD example • Processes are often systematically (hierarchically) broken down into even more detailed DFD.

10. Context Diagram Level 1 Diagram Level 3.1 Diagram Level 1.1 Diagram Level 2.1 Diagram Level 3.1.1 Diagram Level 3.1.2 Diagram “Primitive” DFDs Hierarchical Arrangement of DFDs Balanced: External Flows match at each level Decomposition: At each level, the processes and data flows become more detailed / descriptive

11. QUESTIONS ?

12. 10 minute Quiz