Lead time is a dependency schedule covering specification freeze, materials, samples, approvals, production, inspection and dispatch—not one unsupported promise.
Frame the decision
Build the dates backward from the required handover, name the owner and prerequisite for every milestone, and show approval float separately.
The schedule should show which delayed decision moves the delivery path and which recovery action is genuinely available.
Build the controlled worksheet
Keep these five topic-specific inputs together so the quotation, sample and inspection teams do not work from different assumptions:
- Specification freeze: state the requirement, reference, status and approval owner.
- Material and trim readiness: state the requirement, reference, status and approval owner.
- Sampling and approval rounds: state the requirement, reference, status and approval owner.
- Production and inspection: state the requirement, reference, status and approval owner.
- Packing and dispatch: state the requirement, reference, status and approval owner.
Evidence to request
- Approved source or drawing for specification freeze
- Order-specific record covering material and trim readiness
- Written acceptance basis for sampling and approval rounds
- Controlled decision history for production and inspection
- Release evidence connected to packing and dispatch
Evidence must identify the relevant product, material, revision or lot. Record any limitation, substitution or item still awaiting approval.
Risks to close before approval
- Starting the clock before specifications are frozen
- Assuming immediate buyer sample approval
- Omitting inspection correction or shipping preparation
Assign an owner, due date and written disposition to each unresolved risk. Do not allow an informal answer to replace a controlled revision.
Use the result in the RFQ
Attach the worksheet, quantity, destination, required date and current sample status. Ask the supplier to list assumptions and exceptions against the same five inputs.