Supplier Flow and Replenishment Design

Why it matters

The supplier flow does not cover only the moment the vehicle arrives at the gate. How the need is communicated, when the order is firmed, which container carries the material and where it will be used after receiving are all parts of the same design. Material that has reached the warehouse but is waiting for a quality decision is not stock production can use. The starting point is therefore the moment the order is sent, and the end point is the moment the material is released for its defined use. The waits for preparation, transport, unloading and receiving in between must be visible separately. The lean approach evaluates this flow not by looking at stock quantity alone, but together with its fit to the need and its response to problems. The load that an improvement in one area creates in another area is also part of the decision.

Receiving the same weekly quantity more often can reduce cycle stock under steady consumption. However, every delivery has a fixed transport and receiving load. Vehicle fill can drop, empty containers can pile up, or interruptions at the receiving area can occur more often. A small lot is therefore not good design by itself. Meeting a weekly need of 600 units in three deliveries instead of one means each delivery is 200 units; the total need does not change. What changes is how the quantity is spread over time. The benefit of this spread depends on the deliveries actually arriving in line with consumption. Three vehicles arriving on the same morning do not give the stock effect of three deliveries spread across the week. The quantity total can be right while the timing pattern is wrong.

The information flow is defined before the material flow. The forecast sent to the supplier must be separated from the firm order that authorizes production and shipment. A supplier who reads a forecast as a firm order may produce unnecessarily for a need that later changes. Conversely, transmitting the firm order late creates a preparation gap that a short transport time cannot make up. Which notice is binding, who will approve a change and how a delay will be reported are decided together. PFEP means a plan for every part; it helps keep point of use, consumption, container and replenishment information together. Such a record gives a common starting point in place of disconnected purchasing and warehouse assumptions.

The aim in this lesson is not to choose the most frequent delivery possible; it is to explain the total effect of the feasible options. The comparison is made keeping the same cost scope, the same demand and the same service condition. If the average inventory calculation rests on a steady-consumption assumption, this is written down openly. With irregular consumption, a weekend shutdown or different receiving hours, the timetable is tested separately. Safety stock is not added as an automatic fix for late vehicles; the uncertainty it is held against is stated. At the end of the decision, the chosen delivery rhythm, the responsible people, the response to deviations and the condition for re-review are recorded together. In this way the replenishment plan stops being a number that only states a purchase quantity.

Formula