Some of your classmates will act out the Science Fair system, passing real pieces of paper (data) between them. You are the systems analysts. Your job is to record every movement of data and turn it into a data flow diagram.
The School Science Fair system
• An Entrant hands in a registration form. The system files the project details and gives the Entrant a confirmation slip.
• On judging day, the system makes a judging sheet listing the projects and gives it to the Judge. The Judge returns a completed score sheet, and the scores are filed.
• On results day, the system uses the scores and project details to give Entrants a results list and the Principal a prize list.
Processes are labelled with verb phrases and are numbered. Entities, data stores and data flows are labelled with nouns. Every data flow must start or end at a process.
Every time an actor says “I’m sending … to …”, record it. Write the data as a noun, and say which type of symbol each end is: E entity, P process, S data store.
| # | From (E/P/S) | To (E/P/S) | Data (noun) |
|---|---|---|---|
| 1 | |||
| 2 | |||
| 3 | |||
| 4 | |||
| 5 | |||
| 6 | |||
| 7 | |||
| 8 | |||
| 9 | |||
| 10 | |||
| 11 | |||
| 12 | |||
| 13 |
Name: ____________________________ Group: ______
Draw the whole system as one process numbered 0. Show every entity and every data flow that crosses the boundary. Do not draw data stores.
Open up process 0. Show the numbered processes, the data stores (D1, D2…), the entities and every labelled data flow from your log.
Check: ☐ every process numbered and a verb phrase ☐ every store has an ID ☐ every arrow labelled with a noun ☐ every flow touches a process
List every data flow that crosses the system boundary in your context diagram, then find it in your Level 1 diagram.
| Boundary flow (context diagram) | Entity | In or out? | Same name and direction in Level 1? ✓/✗ |
|---|---|---|---|
The system runs again, but some actors have secret “bug” cards. Record each suspicious move.
| What happened | Rule broken | Name of error | How to fix it |
|---|---|---|---|
A school issues bus passes. A Student sends an application form. The system checks it against student records, issues a bus pass to the student, and sends the Transport Office a monthly pass report.