Clause 6.2.3.5: Evaluate alternative solution classes

Current editionISO/IEC/IEEE 29148:2018, Clause 6.2.3.5Edition 3 at DIS ballotNo public change recorded

Each alternative class is assessed against the available money, time, people and materials, and against the trade space factors recorded earlier.

What clause 6.2.3.5 asks

Each alternative class is assessed against the available money, time, people and materials, and against the trade space factors recorded earlier. The factors become the assessment parameters and the decision criteria. The preferred class or classes are then selected using the project's decision analysis. The clause points to the decision management process in 15288 or 12207 for the method, so the standard does not impose one scoring model.

Why it matters

The assessment is where the analysis becomes defensible. The common failure is a preferred option that is compared only with a straw alternative. The clause expects the criteria to be the ones set before the options were known, and the decision to be recorded with its reason.

What good looks like

Use a simple decision matrix with the trade space factors, their weights and the evidence for each score. Record the sensitivity: which factor would change the choice. Keep the matrix with the decision record.

Evidence an assessor asks for

The assessor will ask whether the criteria were fixed before the scores. A matrix with weights that match the winner is not evidence.

• Decision matrix The classes, the criteria, the weights, the scores and the evidence for each score
• Sensitivity note The factor or weight that would change the preferred class
• Decision record The selected class, the decision maker, the date and the reason
• Resource check The money, time, people and materials assumed for each feasible class

Where it commonly fails

• The preferred class scores highest on every criterion, which usually means the criteria were written for it
• No sensitivity check, so a small change in a weight would reverse the decision
• The decision record names a class but not the decision maker

What to do before the revision

Fix the criteria and weights in the analysis plan before the options are scored. Then record the sensitivity in one line. It is the cheapest defence of the choice.

Read across

• 6.2.3.2 Prepare for business or mission analysis
• 6.2.3.4 Characterize the solution space
• 6.2.3.6 Manage the business or mission analysis
• 6.3.3.4 Develop the operational concept

← 6.2.3.4 Characterize the solution space 6.2.3.6 Manage the business or mission analysis →

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