MA.2:11 - SoTA-Echoing

The selected line combines resource-based managerial costing with the distinction between productive, protective and excess capacity discussed in Tendon and Doiron’s Tame your Work Flow (2020), chapter 7. It adapts the distinction to the actual operating account: the reason for reserve must be established, and elapsed flow time alone does not identify a constrained resource.

In the historical fixture example in Caspari and Caspari’s Management Dynamics (2004), a fixture transfers work between stations: it saves five minutes per unit at one station but adds two at the station that limits production. Total processing time falls from 55 to 52 minutes, while wages remain unchanged. When demand uses the limiting station’s capacity, increasing its work from 25 to 27 minutes per unit reduces possible output. These contributions inform §§4.2–4.3 and the released-hours example.

At the effort of reconciling one resource pool, this account exposes distinctions a utilization percentage hides. More detailed tracking is worthwhile when a capability or time boundary changes the decision. Reopen the account when those conditions or the supply terms change.