PowerPoint Presentation by Charlie Cook Copyright © 2004 South-Western. All rights reserved. Chapter 2 Documenting Business Processes and Information Systems Documenting Business Processes and Information Systems
Copyright © 2004 South-Western. All rights reserved.2–2 Learning Objectives To read and evaluate data flow diagrams To read and evaluate system flowcharts To read and evaluate entity-relationship diagrams To prepare data flow diagrams from a narrative To prepare system flowcharts from a narrative
Copyright © 2004 South-Western. All rights reserved.2–3 Data Flow Diagrams (DFD) Context diagram Top-level diagram Physical flow diagram Internal entity External entity Logical data flow diagram Process and flow of data Systems flow charts Information processes and operations processes
Copyright © 2004 South-Western. All rights reserved.2–4 Data Flow Diagram (DFD) Symbols FIGURE 2.1 NOTES: a. A bubble can be either an entity on a physical data flow diagram or a process on a logical data flow diagram. b. The data store symbol may represent a view—a portion—of a larger entity-wide database.
Copyright © 2004 South-Western. All rights reserved.2–5 A Context Diagram FIGURE 2.2
Copyright © 2004 South-Western. All rights reserved.2–6 A Physical Data Flow Diagram FIGURE 2.3
Copyright © 2004 South-Western. All rights reserved.2–7 A Logical Data Flow Diagram (Level 0 Diagram) FIGURE 2.4
Copyright © 2004 South-Western. All rights reserved.2–8 Balanced Data Flow Diagrams The next five slides depict “balanced” data flow diagrams. Balanced DFDs exist when the external data flows are equivalent. The first DFD is a context diagram and the next one is an “explosion” of it into a level 0 logical DFD. The next diagram is an “explosion” of the logical level 0 DFD, and so on.
Copyright © 2004 South-Western. All rights reserved.2–9 A Set of Balanced DFDs FIGURE 2.5a
Copyright © 2004 South-Western. All rights reserved.2–10 A Set of Balanced DFDs (cont’d) FIGURE 2.5b
Copyright © 2004 South-Western. All rights reserved.2–11 A Set of Balanced DFDs (cont’d) FIGURE 2.5c NOTES: 1. There is no Diagram 2.0, as process 2.0 is an elementary process (i.e., it cannot be exploded further). 2. Assume that bubbles 1.1, 1.2, 1.3, 1.4, 3.1.1, 3.1.2, and 3.2 are elementary processes.
Copyright © 2004 South-Western. All rights reserved.2–12 Systems Flowcharting Symbols FIGURE 2.6a
Copyright © 2004 South-Western. All rights reserved.2–13 Systems Flowcharting Symbols (cont’d) FIGURE 2.6b
Copyright © 2004 South-Western. All rights reserved.2–14 Common System Flowcharting Routines The following slides show several common ways of showing processing using system flowcharting. Pay particular attention to the way the columns are set up to communicate the flow of activities between processing entities.
Copyright © 2004 South-Western. All rights reserved.2–15 FIGURE 2.7a (a) Enter document into computer via keyboard, edit input, record input Common Systems Flowcharting Routines (c) Update sequential data store
Copyright © 2004 South-Western. All rights reserved.2–16 FIGURE 2.7b Common Systems Flowcharting Routines (cont’d) (d)Preparation and later manual reconciliation of control totals
Copyright © 2004 South-Western. All rights reserved.2–17 FIGURE 2.7c Common Systems Flowcharting Routines (cont’d) (e) Key and key verify inputs
Copyright © 2004 South-Western. All rights reserved.2–18 FIGURE 2.7d Common Systems Flowcharting Routines (cont’d) (e) Key and key verify inputs (f) Enter document into computer using scanner (g) Enter document into computer using scanner and manual keying
Copyright © 2004 South-Western. All rights reserved.2–19 Entity-Relationship (E-R) Diagram FIGURE 2.8
Copyright © 2004 South-Western. All rights reserved.2–20 Table of Entities and Activities for Causeway Cash Receipts System TABLE 2.1 EntitiesParaActivities Customers11.Send checks and remittance advices. Mailroom (clerk)12.Endorses checks. Mailroom (clerk)13.Writes amount paid and check number on the remittance advice. Mailroom (clerk)14.Prepares a batch total of the remittance advices. Mailroom (clerk)15.Sends the batch of remittance advices and the batch total to the accounts receivable clerk. Mailroom (clerk)16. Sends the batch of checks to the cashier. Accounts receivable (clerk)27.Enters the batch into the computer. Accounts receivable (clerk)28. Keys the batch total, the customer number, the invoice number, the amount paid, and the check number. Computer29.Verifies the invoice is open and the correct amount is being paid. Computer210.Updates the accounts receivable master data. Computer211.Notifies the clerk of errors. Computer412.Logs check number and amount paid. Computer313.Prints a deposit slip. Cashier314.Compares the deposit slip with the batch of checks. Cashier315.Takes the deposit to the bank. Computer416.Creates a cash receipts listing. Computer417.Prints a summary of customer accounts paid. Accounts receivable (clerk)418.Compares the computer reports with the remittance advices and batch totals. Accounts receivable (clerk)419.Sends the total of cash receipts to the general ledger office.
Copyright © 2004 South-Western. All rights reserved.2–21 Causeway Context Diagram FIGURE 2.10
Copyright © 2004 South-Western. All rights reserved.2–22 Causeway Current Physical DFD FIGURE 2.11
Copyright © 2004 South-Western. All rights reserved.2–23 Table of Entities and Activities for Causeway Cash Receipts System (Annotated) TABLE 2.2
Copyright © 2004 South-Western. All rights reserved.2–24 Causeway Current Logical DFD (Level 0) FIGURE 2.12
Copyright © 2004 South-Western. All rights reserved.2–25 Drawing DFD Diagrams The basic steps of the process are: Create or obtain an accurate and reliable narrative. From the narrative, create a complete table of entities and activities. Draw a context diagram with external entity boxes by distinguishing carefully between internal and external entities. Draw current physical flow diagrams by creating bubbles for internal entities, and showing flows to and from all entities and data stores. Draw current logical flow diagrams by grouping activities that occur together, and naming the logical sub-processes each describes.
Copyright © 2004 South-Western. All rights reserved.2–26 Causeway Systems Flowchart FIGURE 2.13
Copyright © 2004 South-Western. All rights reserved.2–27 Physical DFD for Problem 2-1 FIGURE 2.14
Copyright © 2004 South-Western. All rights reserved.2–28 Logical DFD for Problem 2-2 FIGURE 2.15
Copyright © 2004 South-Western. All rights reserved.2–29 Flowchart for Problem 2-3 FIGURE 2.16
Copyright © 2004 South-Western. All rights reserved.2–30 Entity-Relationship (E-R) Diagram for Problem 2-4 FIGURE 2.17
Copyright © 2004 South-Western. All rights reserved.2–31 Flowchart Segments for Problem 2-9 FIGURE 2.18