Architecture Options Paper
A document presenting multiple architectural approaches to solving a problem, with analysis of each option against defined criteria, enabling stakeholders to make an informed decision on the preferred approach.
Purpose
Options papers ensure that architectural decisions are made transparently with full consideration of alternatives. They provide evidence for governance boards, prevent bias towards a single solution, and create an audit trail of the decision-making process.
When to Use
Create when facing a significant architectural decision with multiple viable approaches, particularly when the decision requires stakeholder or governance board approval. Common during discovery and alpha phases.
How to Build
Define the problem statement clearly — what architectural challenge needs to be resolved? What are the constraints and requirements that any solution must meet?
Establish evaluation criteria before analysing options. These should include both functional and non-functional requirements, cost, risk, time to deliver, strategic alignment, and operational impact. Weight the criteria by importance.
Present 3-5 options (including 'do nothing' where appropriate). For each option, describe the approach, its architecture, technology choices, and how it meets each evaluation criterion.
Score each option against the criteria using a consistent scale. Present the results in a comparison matrix. Identify the recommended option with clear rationale.
Include a risk assessment for the recommended option and outline next steps if approved.
Tips
- Always include a 'do nothing' or 'do minimum' option as a baseline for comparison.
- Use weighted scoring criteria agreed with stakeholders before the analysis.
- Be honest about the weaknesses of the recommended option — credibility matters.
- Include rough cost estimates (order of magnitude) for each option.
- Present options to stakeholders before writing the recommendation to avoid bias perception.
Common Mistakes
- Writing the paper to justify a pre-determined conclusion rather than genuinely evaluating options.
- Not including a do-nothing option, making it impossible to assess the value of change.
- Using evaluation criteria that are biased towards one option.
- Not involving stakeholders in defining the evaluation criteria.
- Presenting too many options (more than 5) which dilutes focus and delays decisions.
Government Context
In UK government, options papers are required for spend control submissions above departmental thresholds. They should follow HM Treasury Green Book appraisal methodology for significant investments. CDDO expects to see genuine alternatives evaluated, not a single preferred option dressed up as a choice. Cross-government shared platforms should always be considered as an option where relevant.