Scope the Model Around the Make-or-Buy Decision

A make-or-buy decision changes what a line study needs to answer. It does not always need to precede the study.

If leadership is comparing internal production with a co-manufacturer, some modeling is part of making that choice. The waste occurs when a team optimizes one configuration while treating the strategic choice as settled.

Separate comparison from detailed design

Start with the alternatives still open: retain the current operation, improve it, transfer some products or outsource the work. Define a common demand and service requirement for the comparison.

Collect the evidence each alternative needs. Internal economics include relevant labor, equipment, quality, inventory and support costs. External economics include quoted service, freight, transition, oversight, inventory and any internal costs that remain.

Allocated overhead is not automatically avoidable when production leaves. Freed floor space has economic value only through a credible use, disposal or avoided future expense.

A model that clarifies those differences is useful even if the plant ultimately outsources.

Name the work that could be stranded

Detailed layout design for a particular loader may be wasted if that line closes. A reconciled demand history or current process map may survive either decision.

Divide the proposed study accordingly. Fund the common evidence and the analysis needed to compare choices. Hold configuration-specific detail until it serves a live alternative, or approve it explicitly as an option with a known cost.

The stopping rule should name the decision owner and the evidence needed. It should not assume that an unresolved decision makes all analysis premature.

Compare the transition, not just the destination

An external quote and an internal steady-state model describe different things unless both include the changeover period. Test inventory buildup, qualification, staffing coverage and the possibility that internal and external production overlap.

Use scenarios when demand or supplier readiness is uncertain. Show which assumptions change the preferred option.

The question for the next study proposal is practical: which decision becomes better because this work exists? If the answer is only that one possible configuration becomes more precise, make the dependency visible before approving the next engineering hour.