VCE Software Development U3O2 Definitions Worksheet: Analytical tools and the software requirements specification (Modules 42–51)
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Key terms
Write what each term means, in your own words.
1
context diagram
2
Level 1 DFD process
3
Data store
4
data flow
5
Level 1 DFD
6
Use case diagram
7
use case
8
<<include>> vs <<extend>>
9
Depicting an existing system
Answer Key
VCE Software Development U3O2 · Modules 42–51 · Student wording will vary for definitions
1context diagram — Shows the whole system as one process, with the external entities around it and a labelled data flow arrow for each piece of data going in or out. Built by reading a scenario.
2Level 1 DFD process — A numbered, named step (e.g. 1.0 Validate Order) in a Level 1 DFD. It uses a verb phrase and shows one main task from the context diagram's single system.
3Data store — On a Level 1 DFD, a data store is where data is held (e.g. a file or database). Entities sit outside the system and send or receive data. Both must match the context diagram.
4data flow — A labelled arrow showing data moving between entities, processes and data stores in a Level 1 DFD. Every flow must start or end at a process, so no entity-to-store flows.
5Level 1 DFD — Breaks a system into processes, data stores, entities and labelled flows found in a scenario, then checks the rules, e.g. every process has an input and an output and no flow is missing.
6Use case diagram — A diagram showing actors (stick figures) outside a system boundary box, linked by lines to the use cases inside the box that they can do with the system.
7use case — A goal an actor achieves with the system. It is drawn as an oval named with a verb phrase (e.g. Borrow Book) and joined to its actor by an association line.
8<<include>> vs <<extend>> — <<include>>: a use case always uses another (arrow points to the included one). <<extend>>: optionally adds behaviour (arrow points from the extending case to the base).
9Depicting an existing system — Using analytical tools like context and data flow diagrams to show how the current system works, so bottlenecks and problems are exposed for the new solution to fix.