Colabmo development course A-P02

Learning objective: Construct bounded principles with explicit premises and avoid turning preferences into universal truths.

A useful working principle states what any acceptable design must accomplish and why. “Use one portal” is a solution. “A decision maker must have the relevant evidence before making the decision” identifies a dependency. Its application still depends on defining relevant evidence and decision scope.

Use this structure: Because these supported premises apply, any acceptable design within this boundary must satisfy this condition. Then add the scope, exceptions and unresolved assumptions. Principles should be few enough to use during design reviews and specific enough to rule out an inadequate proposal.

For the fictional onboarding case, the team might reason: the service must know which legal entity it is serving; the current agreement requires authorization before activation; therefore any acceptable activation design must associate the right entity with an authorization record before activation. This does not establish who types the data or whether checks are sequential.

A principle needs a challenge test. Can you give a plausible acceptable design that violates it? If so, revise the principle, narrow its scope or reclassify it as a preference. Also ask whether the principle is circular. “We need approval because approval is required by the process” explains the current process, not its necessity.

Stop decomposition when the team has premises adequate to distinguish the candidate designs, understands material uncertainty, and can specify tests for that uncertainty. You do not need a philosophical proof of every organizational purpose. You do need to prevent an unsupported premise from silently deciding the design.

Adjacent guidance can improve the discipline without replacing FPT. NASA’s requirements checklist asks whether assumptions are correct and whether requirements avoid unnecessary implementation specifics. Here, that distinction helps separate a needed result from a favored mechanism.

Practice

Use W5 to derive three principles from the onboarding functions. For each, provide two premises, the reasoning connecting them to the principle, and one potential counterexample. Have another pair try to falsify the principle without violating the agreed outcome.

Check your reasoning

Is “Customers must never enter information twice” a sound first principle?