Lifetime Buy
Definition
A lifetime buy (last-time buy or end-of-life buy) is a single final purchase of a component that is being discontinued, sized to cover all expected demand — production, service, and warranty — for the remaining life of the products that use it.
In Practice
Lifetime buys are triggered by supplier end-of-life notices, common in electronics where a chip may be discontinued while the equipment using it must be supported for another decade. The planner must forecast total remaining demand — future builds plus spares and warranty consumption — then add a buffer for forecast error, scrap, and shelf-life limits, and buy it all before the last order date.
The decision is a large, irreversible bet: buy too little and a redesign or brokered parts at 10x cost follow; buy too much and capital sits in stock that may end as excess and obsolete write-off. For a component with 8 years of support life, teams typically model several demand scenarios and weigh the buy against alternatives like qualifying a second source or redesigning the assembly.
Frequently Asked Questions
How do you size a lifetime buy?
Forecast remaining product builds plus service and warranty demand over the support horizon, then add allowances for forecast uncertainty, handling scrap, and storage degradation. Because underbuying forces a redesign or broker purchases at extreme prices, most teams size to a high-confidence scenario rather than the expected case.
What are the alternatives to a lifetime buy?
Qualify an alternate or second-source component, redesign the assembly to remove the obsolete part, arrange continued small-run supply through an aftermarket or licensed manufacturer, or use authorized distributors' long-term storage programs. The lifetime buy wins when redesign cost exceeds the carrying cost and risk of the inventory.
What are the risks of a lifetime buy?
Demand overestimation stranding capital in unusable stock, underestimation forcing costly redesigns or gray-market purchases, and degradation of stored parts — solderability of electronic components, cure dates on elastomers. Mitigations include staged storage conditions, periodic requalification testing, and revisiting the demand model annually against actual consumption.
Related Calculators
Related Terms
A hedge in supply chain planning is a deliberate buffer against a specific uncertainty — extra inventory, forward-bought material, contracted capacity, or a financial instrument — sized and timed to protect against an event rather than routine variability.
Safety StockExtra inventory held beyond expected demand to protect against variability in demand or supply. It acts as a buffer that keeps orders flowing when forecasts miss or deliveries run late.
Dead StockInventory with no recorded sales or usage over an extended period and no realistic expectation of future demand. It occupies space and capital while generating no return.
Minimum Order QuantityThe smallest quantity of an item a supplier is willing to sell in a single order, driven by their setup costs, batch sizes, or packaging units.