Active Review for Intermediate Designs [Clements, 2000] - PowerPoint PPT Presentation

Active Review for Intermediate Designs [Clements, 2000]

• A piloted software design review technique
• A blend of stakeholder-centric, scenario-based, architecture evaluation method (ATAM and ADR)
• Goal: expose design to allow early feedback
• Designers want:
• To know if the design is tenable
• To unveil the design to the community of software writers

• Provides valuable insight into design’s viability
• Allow for timely discovery of errors, inconsistencies, or inadequacies

• Effective technique for ensuring quality, detailed designs in software [Parnas, 85]
• Actively engaging reviewers to utilize the design in a series of exercises
• Conventional design review:
• Examine stacks of documentation
• Checklist to ensure design meets certain standards

• Questions address:
• Quality and completeness of documentation
• Sufficiency, fitness, and suitability of the services provided by the design

• A scenario-based design review techniques
• Scenarios proven to be valuable in the evaluation of system and software designs
• Relies on the present of the stakeholders
• Elicits business goals for system and its architecture
• Uses those goals and stakeholder participation to focus attention to key portions of the architecture

• Benefits:
• Financial gains
• Forced preparation
• Captured rationale
• Early detection of problems
• Validation of requirements
• Improved architecture

Transaction response time (H, M)

Performance

Throughput

150 transactions/sec

Training

Usability

Utility

Normal operations

Database vendor releases

new version

Maintainability

• ADR/ATAM hybrid
• ADR requires active reviewer participation
• ATAM embraced stakeholder-generated scenarios
• Three groups of participants:
• ARID review team (facilitator, scribe, process observer)
• Lead designer
• Reviewers (stakeholders)

• Phase 1: Pre-meeting (between lead designer and facilitator)
• Identify reviewers
• Prepare design presentation
• Facilitator ask “first order” questions
• Identify areas to improve presentation
• Set the pace for the presentation
• A practice to the designer

• Prepare seed scenarios
• Designer and facilitator prepare sample set of scenarios
• E.g. a user in a particular context asks for help, and the system provides help for that context.
• Prepare for the review meeting
• Produce copies of presentation, seed scenarios, and review agenda

• Phase 2: Review Meeting
• Present ARID method (30 mins by facilitator)
• Present design (no questions nor suggestions allowed except on factual clarification)
• Scribe jots down every questions
• Brainstorm and prioritize scenarios
• Perform review
• Provides pseudo code to solve problems posed by the scenario
• Present conclusions

• Initial Architecture
• System overview from a business perspective:
• Most important functions
• Any relevant technical, managerial, economic, or political constraint
• Business goals that relate to the project
• Major stakeholders
• Major quality attributes
• Set of seed of scenarios

• Set of scenarios and their prioritization from the brainstorming
• The Utility Tree
• Issues and problems