Architecture Lifecycle Issues

Architecture Based Process

• Establish business case for the system. e.g. Product cost, time to market.
• Understand the requirements
  • Use cases, prototypes
  • Quality attributes
  • Commonality & variability from previous/future systems - domain analysis.
• Develop the architecture - use tactics, styles.
• Document the architecture - using variety of views and ADL.
• Analyse or evaluate the architecture.
• Implement product based on the architecture.
• Ensure that implementation conforms with architecture.

Process Recommendations

• Architecture should be a product of a single architect or a small group of architects with a single leader.
• Arch should have both functional reqs and an articulated, prioritized list of quality attributes.
• Arch should be well documented with atleast one static view and one dynamic view.
• Arch should be circulated to all stakeholders who should actively review.
• Arch should be analysed for quantitative measures and formally evaluated for qualitative properties.
• Should lend itself to incremental implementation via creation of a skeletal system.

Global Analysis

• The purpose of global analysis is to analyse the factors that influence the architecture and develop strategies for accommodating these factors in the architecture design.
• Three types of factors:

1. Organizational factors
2. Technological factors
3. Product factors

Process

Analyse factors

• 1. Identify and describe factors
  • Consider those that have significant global influence.
  • Can factor be localized or is it truly global ?
• 2. Characterize the flexibility and changeability of the factors
  • Can factor be changed, modified, influenced.
  • How often will it change ? How likely ?
• 3. Analyse the impact of factors
  • Other factors, component, design decisions.

Develop Strategies

• 1. Identify issues and influencing factors
  • Identify handful of important issues that are influenced by factors and their changeability.
  • Usually several factors affect an issue and when they conflict - we must negotiate a change in them.
  • Difficult to satisfy factor, expensive factor.
• 2. Develop solutions and specific strategies
  • Reduce or localize factor's influence.
• 3. Identify related strategies
  • Dont repeat strategies identified with more than one issue. Reference them.

Organisational Factors

1. Management
2. Staff skills

• e.g. Analyze factors
• experience in multithreading.
• Only one developer has skill.
• Flexibility: Subject area is too complex for only training.
• Impact: There is a moderate impact on meeting performance.
• Strategies
• Only 1 developer
• Strategy: avoid use of multiple threads.

1. Process and development environment
2. Development schedule
3. Development budget