Evaluate Build vs. Buy for a Technology Decision
Digital Transformation · 1 week · Intermediate
The job
Make a structured build-vs-buy decision grounded in strategic context rather than engineering preference.
What the sponsor gets
Each canvas and map from this playbook — SWOT Analysis, Assumption Map, Prioritisation Matrix, Pre-Mortem Canvas — exports as a PDF, or as PowerPoint on Pro, straight from the session, and the whole run exports as one PowerPoint for the sponsor. Nothing is redrawn.
The method
Define the requirement clearly
Write a one-page brief covering: what problem this solves, who uses it, what integrations are required, what the timeline is, and what "good enough" looks like. Separate must-haves from nice-to-haves.
Tip: If you can't define "done" in one page, you're not ready to evaluate options — you're still discovering the problem.
Assess your build capability
Create a SWOT canvas for the "build" option. Be honest about your team's capacity, skills, and track record with similar projects. Strengths should reflect proven capability, not aspirational plans.
Tip: If the build option requires hiring, the timeline isn't "when we finish building" — it's "when we finish hiring plus building."
Surface hidden assumptions
Create an Assumption Map for both options. Build assumptions: team capacity, technology choices, maintenance burden. Buy assumptions: vendor longevity, customisation limits, data portability, total cost.
Tip: The most dangerous assumption in "buy" is "we can customise it later." The most dangerous assumption in "build" is "it'll take 3 months."
Score the options
Create a weighted scoring matrix with criteria from your brief: fit, cost (3-year TCO), time to value, integration complexity, vendor risk, and strategic control. Score each option honestly.
Tip: Include the cost of maintaining a custom build for 3 years, not just building it — maintenance is 60–80% of the total cost of ownership.
Pre-mortem each option
Run a quick pre-mortem for the leading option. "We chose to [build/buy] and 12 months later it's been a disaster. What happened?" This reveals the risks the scoring matrix doesn't capture.
Tip: For "buy" failures, focus on vendor lock-in and hidden costs. For "build" failures, focus on scope creep and key-person dependency.
Make and document the decision
Present the analysis to the decision-makers. Document the decision, the reasoning, the key assumptions, and the conditions under which you'd revisit it. This prevents relitigating the decision every quarter.
Tip: Set a 6-month review date to check whether the key assumptions are holding — the best decision now might not be the right decision forever.
The canvases and maps
- SWOT Analysis
- Four quadrants split inside from outside and helpful from harmful, so strengths cannot hide threats and every point has to land somewhere.
- Assumption Map
- Assumptions plotted by importance and certainty, so the leaps of faith that need testing first stand apart from the safe bets.
- Prioritisation Matrix
- Impact against effort in four quadrants — quick wins, major projects, fill-ins and avoid — so the team trades off instead of calling everything a priority.
- Pre-Mortem Canvas
- It starts from failure — the project, how it failed, root causes, mitigations and early warnings — so people can voice doubts as foresight rather than dissent.
What it doesn't do
It doesn't run the room for you or decide for the client. The steps, canvases and duration are a starting point you adapt; the judgement stays yours.