In brief
A last time buy is the final chance to order a discontinued product, buying the remaining demand for the rest of its service life.
Contents
What is Last time buy?
After a discontinuation, manufacturers set a date up to which the product can still be ordered. By then, customers must estimate how many units they will need for the rest of the plant's planned service life. This is often followed by a later date for the final delivery, the last time ship.
Calculating the quantity is the real challenge. Historical consumption, the number of installed units, the expected failure rate, the remaining service life of the plant, planned modernisation and a buffer for uncertainties all need to be taken into account. Buying too few parts leads to shortages later; buying too many ties up capital and can lead to deterioration where shelf life is limited, for example with elastomers, batteries or electrolytic capacitors.
A last time buy is a bridge, not a permanent solution. It buys time to prepare a modernisation or a qualified alternative part.
In practice: maintenance and procurement
For last-time-buy parts, storage conditions and shelf life should be documented. Anyone who misses the deadline is dependent on remaining stock at distributors or other users, which is often difficult to find.
Synonyms and abbreviations: LTB · lifetime buy · end-of-life buy · last order date (LOD)
Frequently asked questions
How do you calculate the quantity for a last time buy?
A simple approach: expected annual consumption multiplied by the remaining years of use, plus a safety buffer, minus existing stock. Example: with 4 failures per year, 6 remaining years and a 20 % buffer, the requirement is around 29 units; if 5 are already in stock, about 24 are ordered. Rising failure rates in ageing equipment should be taken into account.
What is the difference between last time buy and last time ship?
The last time buy date is the last day on which an order is accepted. The last time ship date is usually later and marks the manufacturer's final delivery. For planning, the order date is decisive: by then, quantity, budget and internal approvals must be settled, even if the goods only arrive months later.
Who should be involved in the decision on a last time buy?
Maintenance knows consumption and failure behaviour, production the planned remaining life of the equipment, purchasing the deadlines and terms, and controlling the capital tied up. If the decision is made jointly and documented together with its assumptions, it can be traced later, for example if operating lives change or remaining stock has to be valued.