Pool material and demand only where specifications and risks permit it

A network can duplicate protection without duplicating a warehouse code. A hub may size its buffer from factory orders, while each factory sizes its own buffer from end demand and uncertainty about the hub. If those decisions are made independently, both stages can protect against the same downstream deviation. The factory orders also contain batching and replenishment logic, so they are not an independent demand process that can simply be added to end-customer variability. A coordinated comparison needs one network boundary and a shared service definition.[S05][S07]

Installation stock answers a local question: what accepted quantity is held at this location under the stated status rules? Pipeline stock is moving between locations and is not yet usable at the destination. Customer backorders are unfilled obligations, not negative physical stock on a shelf. Echelon stock looks across a defined downstream network boundary so that inventory and commitments can be coordinated without treating each location as an isolated business. Distribution planning provides the location-and-time structure; the precise accounting convention must still be declared.[S07]

For a proposed GFT echelon view, physical stock within the boundary is counted once, whether it sits at the hub, a downstream site or an internal transfer buffer. Firm inbound receipts are shown separately until they qualify under the planning rule. Backorders reduce the echelon inventory position under the selected convention but never turn quarantined or rejected goods into usable supply. Returns await inspection rather than being added immediately to sellable stock. These are control definitions for comparison, not claims that one formula fits every contract or accounting system.[S07][S09]

The comparison should then run the same demand and supply paths through both policies. Independent local buffers form the comparator, not an assumed inefficient straw case. The coordinated policy may place a common buffer upstream, preserve a small local response quantity and allocate against visible downstream positions. It wins only if end-customer service, total usable stock, cash exposure and exception outcomes improve under the agreed measures. A reduction at the hub accompanied by larger factory shortages is not a network improvement.[S05][S07]

A decentralised policy can remain preferable. Long or unreliable transfers, weak stock visibility, different local promises and frequent urgent requirements may make upstream coordination too slow. Local ownership can also make discrepancies easier to investigate. The purpose of echelon analysis is not to prove that central control is superior. It is to reveal where uncertainty is protected, where inventory is counted and which stage has authority when the plan becomes infeasible.[S01][S07]

Supplier count is not the same as independent supply. Two vendors may buy from the same upstream mill, use the same port, depend on the same power or communications infrastructure, or subcontract to the same specialist process. A garment network can therefore appear diversified at the first contractual tier while remaining concentrated at the point that actually determines usable receipt. The OECD notes that subcontracting is common in garment and footwear supply chains, which makes indirect stages a necessary part of the dependence map.[S25]

The same caution applies to pooled inventory. A single hub may serve several demand points efficiently during ordinary variation but concentrate exposure to a site outage, system failure, transport interruption or quality hold. Separate local stocks can contain some events, while a common pool can deplete everywhere after one upstream shock. The choice is not between resilience and efficiency as slogans. It is between explicit failure modes, quantities and recovery times under each design.[S05][S24]

Probability notation makes the missing evidence visible. If A and B are the events that two sources are usable when required, the probability that at least one is usable is P(A or B) = P(A) + P(B) - P(A and B). Independence would simplify the joint term, but it is precisely the assumption that a shared mill, route or subcontractor can invalidate. The planner needs evidence about the intersection, not just each supplier's separate on-time history.[S05][S25]

Stochastic lead-time research provides another warning against convenient assumptions. The opened manuscript analyses models with independent and identically distributed lead times while also discussing their limitations and the need to study dependence between lead times and demand. It does not establish that any garment supplier has independent delays. GFT would use such models as scenario structures and test their assumptions against usable-receipt observations.[S24]

A stress design should contain at least three distinct paths: ordinary separate delays, a shared upstream or corridor event, and loss of the pooled location or conversion process. The first path tests routine buffers. The second tests whether apparent source diversification survives common dependence. The third tests concentration created by the network itself. Each path should record which customer promises fail, which substitute is technically approved, how much stock remains usable and who may authorise emergency allocation. No probability needs to be invented to make those actions inspectable.

Qualification must precede the emergency. An alternate source needs the same specification, test-lot, capacity and usable-receipt checks as any other source, together with a map of its upstream dependencies. A second contact in a procurement database is not a qualified recovery route. If both qualified sources share an unavoidable dependency, the policy should say so and consider a different material, route, stock position or customer promise rather than assign false independence.[S07][S25]

This analysis can also change the demand-pooling result. A common disruption may raise demand for substitutes at the same time that it restricts supply, producing adverse correlation between requirements and availability. The calm-period covariance estimate would then overstate pooling protection precisely when the buffer is most needed. GFT would therefore report ordinary-demand pooling and shared-shock stress separately, with no claim that one historical correlation coefficient covers both.[S05][S24]

Pooling changes incentives as well as quantities. A supplier-owned buffer, a factory-owned hub, distributor stock and consignment arrangements allocate ordering authority, payment, loss and obsolete material differently. Supply-chain contract analysis shows why the allocation of overage risk matters to ordering incentives and why a buyback or return right must be assessed across the chain. A contract can move exposure without removing the physical units or the uncertainty that created them.[S08]

The decision record should state who forecasts, who may release replenishment, when quantity becomes binding, who owns stock at each stage, who pays for carriage and storage, and who may return or redirect residual units. It should also define damage, shrinkage, quality rejection, specification change, termination and dispute treatment. Visibility is a separate field: a party that owns stock may still lack timely quantity and status information, while a party without title may carry the operational consequence of a shortage.[S07][S08]

Consignment is a clear example of why factory stock and whole-chain stock must be reported separately. Moving material to a supplier's balance sheet may reduce the factory's recorded inventory or change its cash timing, but the material still occupies a location and may still be reserved for the same customer promise. Conversely, shifting finished goods to a distributor does not prove that end demand has been served. The network review should count physical quantities once and show ownership as an additional dimension rather than using ownership to erase stock.[S07][S08]

Residual value requires equal care. IAS 2 states that inventories are measured at the lower of cost and net realisable value, which provides accounting context for write-down exposure. It does not tell the network which pooling policy is operationally preferable, and applicable reporting treatment needs professional confirmation. A pooled generic input may retain more recovery options than differentiated variants, but that advantage depends on actual alternative uses, approval rules and selling or recovery costs.[S09]

A whole-chain review should also ask how the apparent improvement was obtained. The ILO's global supplier survey motivates attention to purchasing practices and working conditions, while its age, voluntary response and international scope prevent any inference about current Cameroon prevalence. Within this chapter, the implication is narrow: do not describe lower factory inventory as a clean gain if it depends on unexamined supplier pressure, unrealistic changes or unpaid recovery work.[S10]

The final network choice should present a frontier rather than a universal answer. A central generic-material pool may suit compatible inputs, offsetting demand and reliable conversion. Local buffers may dominate where promises are short, routes unreliable or failure containment matters. A mixed design may be appropriate when local response stock and upstream contingency stock protect different horizons. In each case, the recommendation remains conditional on measured service, feasible conversion, visible stock and an accountable owner for what remains.[S01][S05][S07]