Lead time is confirmed in writing or it is not known

A lead time is a date on a quotation, or it is unknown. The selection you are making is which timing statement is strong enough to plan a sample collection, a grant milestone, or a receiving roster around. Catalogue adjectives, a colleague's last shipment, and a sentence in a call do not reach that bar. A date that is not written down is not yet a date. The enquiry that asks for the date to be written is how to write a laboratory sourcing enquiry. Send it through laboratory procurement. University groups can begin at academic research. Use a quotation request or contact. A scope can be discussed. This page does not invent durations, and it does not describe any item as waiting on a shelf.

Choose the date you can defend

You will brief other people. A student will book a trip to collect tissue. A core facility will hold a slot. A procurement office will ask why the file is urgent. The only timing you can defend in that conversation is the timing a quotation stated, with the event that starts the count. If you cannot point at that sentence, say the lead time is unknown and plan the work that does not depend on the item. Pretending is how a Thursday collection becomes a wasted sample.

Selection here is not a ranking of sellers by speed. You do not have speeds except the ones written. Selection is a filter: keep statements that name a calendar date or a counted interval from a defined start; set aside everything else until a revision writes it down.

What counts as written

A calendar date counts when the quotation says the goods or the data will be delivered by that date, and it says delivered to where. "By 18 November at the laboratory receiving desk" is a date. "By November" is a month. Use the precision that was written, not a tighter one you infer.

A counted interval counts when both the number and the start are written. "Twenty-one days after we receive a complete order" is a lead time. "Three weeks" with no start is a fragment. "After dispatch" is a start that ignores how long dispatch itself takes, unless dispatch is also defined. Read the sentence slowly enough to find the start.

A window counts as a window. If the quotation says fifteen to thirty days from order, your hard deadline should be tested against day thirty, not against day fifteen. Hoping for the near end is allowed as a hope. Briefing it as the plan is not.

Silence counts as unknown. So does a word that sounds temporal and names nothing: soon, priority, usual, short. None of those is a date. A date that is not written down is not yet a date.

Criteria for accepting a written date

Use four checks before you let the date into the plan.

First, the start event is something you can observe. Order acknowledgement, receipt of qualified samples, or a named approval are observable. "Once everything is fine" is not.

Second, the end event is delivery of the thing you specified, not a milestone inside the seller's building. A manufacturing date you cannot see is a weak end event unless the quotation also states the handoff to you.

Third, the date covers the configuration you asked for. A date for a standard reagent is not a date for the same reagent with a certificate you added later. If you change the specification, the date expires and you need it written again.

Fourth, the date is on the quotation or on a revision you file with it, not in a mail that contradicts the quotation and was never incorporated. Mail can become the revision if you ask for the quotation to be reissued and it is. Until then, the quotation stands.

ISO 9001 talks about organisations agreeing requirements they can trace. You do not need that standard to insist on a sentence. It is a public cousin of the same habit. NIST laboratory metrology is a reminder from a different trade: a number without a defined method is not yet a measurement. A duration without a defined start is not yet a lead time.

A grant date and a silent quotation

Suppose a progress report needs a western blot from a new antibody, and the report meeting is on a date you can point to. The enquiry asked for the antibody, the clone or the performance lines, the storage class, the certificate, and a delivery date counted from order. The quotation returns the antibody identity and the certificate, and it says nothing about timing. A sales note in the margin of your inbox says the item "usually moves quickly".

The filter rejects the inbox sentence. The lead time is unknown. You do not fill the unknown with a duration from a previous antibody, because that duration was about a different product and may not even have been written down then. You write back and ask for a date or a counted interval from a named start, on a revised quotation.

Meanwhile you select the work that is honest. You can prepare lysates, check the gel system, and write the blot protocol. You cannot promise the report will contain that blot. If a revised quotation later states thirty days from order, you compare day thirty with the meeting. If day thirty is after the meeting, the written date has done its job: it told you the blot is not a commitment you can make. You might discuss a smaller specification that the seller can date earlier. You do not instruct anyone to talk as if the original silence had been a short wait.

If the revised quotation states a date before the meeting, you still plan receiving. Someone must be present to accept a frozen or refrigerated class, record the condition, and move it into the right storage. That labour is yours. The quotation's date does not staff your dock.

When the written date moves

A date can be revised. The new date replaces the old one only when it is written with the same clarity. Keep both documents so you can see the movement. Do not average them. If the new date misses the scientific need, reopen the design: fewer samples, a different reagent class, or a milestone that no longer depends on this item. Anger is not a selection criterion. The written date is.

If samples are perishable and the date slips past their life, the study design has to change on purpose. Do not collect the tissue on the hope that the slip will reverse itself. A date that is not written down is not yet a date, and a date that was withdrawn in writing is no longer the date.

Failure modes

The first is borrowing a duration. Last quarter's enzyme took a certain time, or you believe sea freight "usually" takes a certain time. Neither fact is written on this quotation. Using it launders an anecdote into a plan. This page will not supply a replacement anecdote.

The second is starting the clock in your head. You ordered on Monday and the quotation said twenty-one days from acknowledgement, and nobody has acknowledged. The twenty-one days have not started. Ask for the acknowledgement in writing rather than assuming Monday was close enough.

The third is hiding a slip. The revised date is worse, so the slide for the group meeting keeps the old one. That is how a laboratory briefs a false date. Show the revision. Select a scientific response.

Safety, samples, and the institution

A written date does not make a shipment safe. Temperature class, containment, and who may open a package remain scientific and institutional questions. The WHO laboratory biosafety manual places biosafety decisions with the institution. If the date says samples will travel, your biosafety office still decides whether that travel is allowed. Research timing is not a clinical service promise. Do not let a short written date pressure anyone to skip a containment step.

Receiving in the heat, without inventing transit

You can plan the dock without knowing a ship duration you were never given. If the quotation states a date, staff the receiving hours around that date, and write into the enquiry the hours someone can actually accept a cold box. Afternoon heat and a locked building after a certain hour are local facts. They are reasons to specify receiving, not reasons to invent how many days a carrier takes. If the quotation states no date, do not staff a fictional day. A date that is not written down is not yet a date.

What the enquiry asks the quotation to state

Ask for one timing sentence: a calendar date, or a number of days from a start event you can see, ending at delivery to a named place. Ask the seller to leave the sentence off rather than fill it with a mood. Put the performance lines and the document set in the same file, because a date for the wrong item is not the date you need. Route the file through laboratory procurement or academic research, and send it by quotation request or contact. A scope can be discussed. When the answer arrives, apply the filter again. Brief only what survived.