1. Introduction Process Modeling with Data Flow Diagrams (DFD)

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

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

4. Sample Graphical Tools for Modeling Organizations l PEOPLE: Organization Chart (a.k.a. "Org Chart") –hierarchal people model –shows who reports to whom l DATA: Entity Relationship Diagram (a.k.a. "ERD"): –data only model –no people, hardware, flows or processes l 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 l 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 l 2 Types of “Activity”: an action being performed by an internal or external entity. –Information processing (DP) actions: transform datatransform data retrieve data from storageretrieve data from storage filing datafiling data document processingdocument processing data entrydata entry verificationverification classificationclassification arrangement or sortingarrangement or sorting calculatingcalculating summarizingsummarizing –NOT information processing (NDP) actions: Sending & receiving data between entities are NOT information processing 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.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) l A graphical representation of a business system or subsystem that shows how system components (entities, activities and data) are interconnected.

7. More DFD Terminology l Business Process –An activity that converts inputs into outputs –Verbs rather than Nouns –Types: DP vs NDP l Data Flow –Data moving from one place to another without being transformed –a.k.a. pathway for data l Data Store –A data flow at rest l 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. DFD Symbol Sets l Process l Data Flow l External Entity l Data Store Customer Completed Orders or Completed Orders or Customer Yourdon-DeMarcoGane-Sarson 1.0 Enter Report Parameters 1.0 Enter Report Parameters Project Managers Customer Order

9. Two Types of DFDs l 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: Context ExampleContext Example l 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 flowsHow “processes” transform input data flows into output data flows How “data” move through an information systemHow “data” move through an information system –Logical DFD Example / Physical DFD example Logical DFD Example Physical DFD exampleLogical DFD Example Physical DFD example –Processes are often systematically (hierarchically) broken down into even more detailed DFD. more detailed DFD more detailed DFD

10. Sample Context DFD Provides an overview of the entire process (e.g. Cash Receipts Process) and the external entities the process interacts with. Will have one or more flows coming into process and one or more flows exiting process BACK to Types of DFDs Slide Back to Slide 13Slide 13 (Logical DFD Example)

11. Sample Logical DFD (What) Focus on WHAT is being Transferred e.g. Sales Record. Doesn’t address the FORM of the exchange e.g. paper sales summary? “Balanced” DFDs : External Entities and External Data Flows must match at each level in hierarchy. Context Example.Context Example BACK to Types SlideBack to Context DFD

12. Sample Physical DFD (How) This explains the FORM the sales data takes (it is scanned) WHO does the scanning (sales clerk) and WHERE scanned data go (computer) 3 Internal Entities BACK to Types SlideBACK to Slide 14 Physical ExampleSlide 14

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

14. QUESTIONS ?

15. 10 minute Quiz