Diagnose repeated supplier delays by tracing the promised date through order acceptance, materials, production, dispatch and receipt, then price the failure.
Short answer: Your supplier is usually late because the date was never accepted against a complete order, capacity or material was assumed rather than reserved, production started later than reported, or dispatch time was mistaken for arrival time. Trace the last three orders through five dated milestones, then require evidence at the first point of variance. As a working escalation rule, reduce exposure after two unexplained misses in three comparable orders, sooner when one failure threatens safety, legality or an unrecoverable sales window.
“Delivery expected Friday” can mean you requested Friday, the supplier plans to dispatch Friday, or a carrier estimates arrival Friday. Those are different promises. If you measure only the final miss, every cause looks like a courier problem.
Repeated lateness is not a communication problem once you have asked clearly. It is an operating capability that must be measured and priced.
Use the Promise-Date Variance Trace
The Promise-Date Variance Trace is a diagnostic framework that follows each order through five milestones. Record planned and actual dates, then find the first gap. The first gap usually identifies who must change what.
- Complete order received: Evidence: Accepted purchase order, specification and artwork; Common cause of variance: Missing decision, vague quantity or unapproved file; Corrective action: Use a completeness check before requesting a date
- Material available: Evidence: Allocation or material receipt confirmation; Common cause of variance: Supplier assumed stock or upstream source slipped; Corrective action: Reserve material or expose its lead time
- Production starts: Evidence: Dated job record or inspection evidence; Common cause of variance: Capacity was sold twice or another job took priority; Corrective action: Book a slot and set a start trigger
- Goods ready and dispatched: Evidence: Inspection, packing list and carrier collection; Common cause of variance: Rework, incomplete quantity or missed collection; Corrective action: Set a readiness milestone before customer promise
- Goods received: Evidence: Carrier scan and your intake record; Common cause of variance: Transit, customs, address or receiving delay; Corrective action: Add measured transit and receiving time
Do this for the last three late orders. Do not begin with explanations. Begin with dates and evidence.
My position is that you should replace a repeatedly late supplier even when their unit price is lower, unless they expose the cause, agree a measurable correction and meet the next two milestones. Loyalty to a price list is expensive when customers experience the delay.
Establish which date was actually promised
Put four fields on every purchase order or confirmation:
- order complete date, when the supplier has everything required
- confirmed production-complete date
- confirmed dispatch date
- required arrival date at the named destination
Ask the supplier to accept or amend these in writing. “Lead time: three weeks” is incomplete until you know when the clock starts, whether weeks are working weeks, and whether transit is included.
If you send final artwork five days after ordering, the original date may no longer apply. If the supplier accepts a revised date without checking capacity, the failure is theirs. The trace separates the two.
For every change, record its effect on the promised dates. A friendly “no problem” is not a schedule update.
Locate the first variance, not the final excuse
Suppose an order arrives four days late. The carrier may have taken one extra day, but production began six days after the agreed start. The courier did not cause the commercial miss.
Ask for a simple variance account:
- Which milestone first moved?: Useful answer: “Material arrived 12 May, three days after allocation”; Weak answer: “There were delays”
- By how much?: Useful answer: Planned 9 May, actual 12 May; Weak answer: “A few days”
- Why did that happen?: Useful answer: Named upstream batch failed inspection; Weak answer: “High demand”
- What prevents recurrence?: Useful answer: Second material allocation confirmed by a stated date; Weak answer: “We will monitor it”
- Who owns the action?: Useful answer: Production manager named on confirmation; Weak answer: “The team”
You do not need access to every factory record. You need enough dated evidence to decide whether the explanation is consistent and the correction is observable.
Check whether your forecast and order behaviour contribute
Suppliers cannot reserve capacity around an invisible order. An eight-to-twelve-week rolling forecast is an indicative starting horizon, not an industry benchmark. Replace it with the period that covers your own confirmed lead time and meaningful demand variability, clearly distinguish likely volume from committed purchase orders, and confirm the supplier's capacity response.
Then audit your side. Count late artwork, specification changes, approval delays, split instructions and payment holds. If two of the last three orders were incomplete at the requested start date, correct your order release before escalating supplier performance.
Forecasts are not orders unless your agreement says otherwise. Equally, a supplier should not describe capacity as available if it will only be allocated after a later deposit or material approval. Write the reservation trigger down.
Avoid padding every requested date by two weeks without fixing the cause. Hidden buffer becomes invisible capacity that both sides eventually consume. Hold an explicit contingency based on measured variability and tell customers a date you can support.
Price lateness as part of supplier cost
Unit price comparisons hide rush freight, idle staff, partial shipments, customer discounts, lost sales and founder time. Maintain a late-delivery cost record by order.
Count only consequences you can defend. If a customer would have bought later anyway, do not call the full sale lost. Use contribution rather than revenue when estimating genuine lost orders. Record internal time at an agreed cost rate so repeated expediting becomes visible.
Compare that annual failure cost with the saving against a reliable alternative. A supplier charging less per unit can still be your higher-cost source.
Worked example: Cedar Row Uniforms
Cedar Row Uniforms buys 2,000 blank work shirts a year from a supplier that is £0.45 cheaper per shirt than a verified alternative.
Annual quoted saving = 2,000 × £0.45 = £900.
Across four late batches, Cedar Row records the direct consequences:
- Four emergency part-shipments: Calculation: 4 × £185; Annual amount: £740
- Idle embroidery labour: Calculation: 18 hours × £24; Annual amount: £432
- Customer discounts on delayed orders: Calculation: Recorded credits; Annual amount: £310
- Total evidenced lateness cost: Calculation: £740 + £432 + £310; Annual amount: £1,482
Net supplier disadvantage = £1,482 lateness cost - £900 unit-price saving = £582.
The trace shows that all four orders entered production after the confirmed start date. The first explanation was transport, but carrier collection occurred on the day after production actually finished. Cedar Row gives the supplier one corrective cycle with a dated production-start confirmation. It also moves 25% of the next order to the alternative. When the milestone slips again, the business transfers the remaining volume.
The £582 excludes founder chasing time and any reputational damage because Cedar Row cannot measure those reliably. The decision works without inflated assumptions.
Match the response to the failure pattern
Use the cause, not your frustration, to choose the remedy.
If order inputs are incomplete, standardise the purchase release and assign one approver. If material is the constraint, reserve it, approve a substitute or hold calculated buffer stock. If production start slips, seek a booked slot, staged evidence or a second source. If goods are ready but collections fail, change carrier arrangements or collection cut-offs. If transit is variable, promise from actual receipt data rather than the supplier's dispatch estimate.
For chronic overpromising, reduce order exposure. Smaller or split batches will not repair capacity, but they reduce the amount trapped when dates move. A qualified backup creates a route out.
Do not impose penalties you cannot enforce or that merely encourage the supplier to hide delays. A service credit can compensate part of a loss, but it does not deliver the missing stock. Have material contract terms reviewed by a qualified solicitor.
Related guides
Run a ten-working-day correction
Today, trace the last three orders and calculate each first variance. Within two working days, send the supplier the dated record and ask for its evidence, root cause, owner and corrective milestone.
By day five, agree the next order's complete, production, dispatch and arrival dates. Set evidence for the critical start point. At the same time, obtain a sample and current lead time from one alternative supplier. Review the milestone on day ten or the agreed start date, whichever comes first. If the supplier misses it without a new, evidenced cause, reduce the next allocation. Do not wait for another customer delivery to fail.
Frequently asked questions
How many late deliveries should I tolerate?
Use two unexplained misses within three comparable orders as a working escalation rule, not a general supplier benchmark. One disruption can be exceptional if the supplier identifies the first variance, communicates before the deadline and implements a credible correction. Repeated misses accompanied by new excuses show that the promise process is unreliable in practice. Set a tighter tolerance where one late safety-critical or seasonal order could cause irreversible harm. Qualify an alternative while testing the correction, not after it fails.
Should I ask for a discount when a supplier is late?
Ask for compensation where your terms support it and the amount reflects a real failure, but fix continuity first. A discount can reimburse rush freight or agreed service failure; it cannot restore missed customer dates. Document the actual loss, the promised milestone and the supplier's variance before negotiating.
Avoid accepting a small credit in exchange for waiving a larger contractual remedy without advice. If discounts recur, add them to the supplier's cost record. A cheap late order is still late, and recurring credits may conceal that the source is operationally unsuitable.
Is extra buffer stock the best solution to late suppliers?
Only when delay is variable, the item remains usable and the holding cost is lower than the contribution protected. Calculate daily usage, replenishment variability and the cost of financing, storing, damaging or obsoleting the extra units. Buffer stock can cover a five-day transit swing.
It cannot solve systematic quality failure, a discontinued component or a supplier with no production capacity. Make the buffer explicit and review it after each cycle. If you constantly consume it, you have not built contingency; you have lengthened the normal lead time without correcting the source.
How do I know whether the supplier or courier caused the delay?
Compare the confirmed dispatch milestone with the carrier's first collection scan and the confirmed arrival date. If the goods were handed over late, the production or collection arrangement failed before transit began. If collection was on time but movement or delivery exceeded the quoted service, investigate the carrier route, address, customs and receiving availability.
Also check whether “dispatch” meant a label was created rather than goods were collected. Record both events. Your supplier remains responsible for the delivery commitment to the extent your contract assigns it, even if a subcontracted carrier caused the operational variance.
Should I tell customers the supplier's promised date?
No. Give customers a date built from your confirmed readiness milestone, measured transit, receiving work and an explicit contingency. The supplier's date is an input to your promise, not the promise itself. If you have no delivery history, use a conservative range or avoid committing until dispatch evidence exists.
Once performance stabilises, adjust using your records. Do not blame a named supplier when speaking to customers. You chose the supply arrangement and should communicate the revised date, customer options and remedy clearly. Internally, preserve the evidence needed to recover costs or change source.
What should I include in a supplier performance review?
Review complete-order acceptance, confirmed versus actual production start, dispatch and arrival dates, first-pass quality, quantity accuracy, response time and total failure cost. Use the same definitions for every order. Discuss the three largest variances, their root causes, action owners and due dates.
Include your own late approvals or forecast errors so the review remains credible. Do not average away a severe seasonal miss with several easy on-time orders. Finish with a clear allocation decision for the next cycle. A review without a consequence becomes a conversation the supplier can safely ignore.
When is it time to replace the supplier completely?
Replace them when the first variance repeats after an agreed correction, they will not provide evidence, the total failure cost exceeds their commercial advantage, or the risk to safety, legality or customer retention is intolerable. Move in controlled stages where possible: approve the alternative, validate a batch, transfer a share, then close the old route after acceptance.
Immediate cessation may be necessary for fraud, serious safety concerns or material breach, but obtain professional advice on contracts and regulated products. Do not threaten replacement before the alternative can actually supply you. Dependence weakens the threat and your operation.
Comments (0)