C.32.LCA:4.5 - Compare serious architectural alternatives

Retain alternatives that change the mechanism, not just the labels. The following are recurring choices, not an exhaustive classification.

A command or reference governor adjusts the requested input to an already qualified closed loop using its current condition and applicable constraints. It is an alternative to redesigning that loop.

Alternative	When it can answer the question	Cost or limit to examine
One controller or one timely decision point	The needed information and action rights are available together, and the computation or decision fits the useful window.	Information collection, scarce attention, computation and response delay can become limiting.
An already qualified loop with a command or reference governor	The loop’s response is adequate, but requested commands can violate its qualified conditions.	The governor can delay or alter the requested outcome; it needs an applicable model and admissible initial situation.
Layered planning and correction	Different decisions need different horizons, representations or response times, and a useful interface can preserve their dependence.	Model mismatch, stale information, repeated computation, interface constraints and delay must be included.
Local decisions with coordination of shared conditions	Participants can act independently within allocations or agreements, while specified interactions need reconciliation.	Negotiation, conflicting commands, duplicated reservations and unavailable authority can defeat apparent autonomy.
Change the work or the physical arrangement	Removing a dependency, changing a capability or changing the demanded result costs less than coordinating the existing arrangement.	Transition cost, lost flexibility, changed commitments and consequences for other users remain part of the comparison.

Use C.32 to develop the candidate palette when several structures change together. For an identified conflict across scopes, C.32.MLAO helps generate alternatives that reduce it while exposing the burden moved elsewhere. Bring those candidates back to the information, timing and joint-condition construction here.

A policy in a lower control layer need not be less accurate than a decision in an upper control layer. Rapid tracking accuracy, predictive accuracy, semantic understanding, search quality and adaptability are different characteristics. Compare the required characteristics under the actual resource conditions. A rule such as “strategy is slow” is a possible arrangement, not a substitute for that comparison.