Session 4.3 - Design Standards & Representation
Chapter 7: Designing with Teams | Duration: 1 hr
Learning Objectives
By the end of this session, you will be able to:
- List key design standards (naming, interfaces, messages, defect types)
- Explain why design representation standards matter
- Use scenarios and state analysis to improve design quality
- Apply PSP templates or equivalents to ensure completeness
Introduction
Standards keep team designs consistent and reviewable. Chapter 7 highlights naming, interfaces, messages, defect types, LOC counting, and representation—plus scenario and state analyses to catch logic issues.
Key Design Standards
| Standard | Description / Purpose |
|---|---|
| Naming conventions & glossary | Hierarchy for system/product/component/module/object; file/variable/parameter names; glossary maintained by support manager. |
| Interface formats | Consistent parameter roles (input/output/errors), error codes, and formats to reduce mistakes and ease reviews. |
| System & error messages | Standard formats and reusable messages for clarity and usability. |
| Defect types | Use PSP defect type standard (Table 7.1) for consistent logging and analysis. |
| LOC counting | Needed early for some projects (e.g., counters/analyzers); otherwise defined in implementation. |
Design Representation
An imprecise or ambiguous representation leads to implementation and test issues. Define what “complete design” means up front.
PSP Templates (examples)
- Operational scenario template
- Functional specification template
- State specification template
- Logic specification template
Use these or equivalents; completeness and precision matter most.
Use Cases / Scenarios
Scenarios describe externally visible behavior: input sequences and system responses (normal and erroneous). Benefits:
- Surface usability and design questions early
- Provide seeds for integration/system tests
- Clarify expected flows for reviewers
State Analysis
Use state machines to uncover complex logic, especially across cycles. Helpful when behavior might become contradictory after enhancements.
Summary
- Set standards early: naming, interfaces, messages, defect types, LOC counting.
- Adopt a clear design representation; ensure every design is complete and reviewable.
- Use scenarios and state analysis to find logic and usability issues before implementation.
- Support manager maintains glossary and standards; all team members follow them.