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Focus
What It Enables
→ Evaluate continuity and mitigation options
→ Informed decisions with options and trade-offs
→ Analyze lifecycle costs and risks
→ Investment and redesign planning
→ Govern lifecycle investment decisions
→ Long-term support planning
→ Plan long-term product and service continuity
→ Product and service continuity
Lifecycle Visibility
Identify changes that affect future availability.
Continuity Planning
Evaluate options for maintaining long-term support.
Decision Analysis
Compare alternative strategies and business impacts.
Inventory Strategy
Protect inventory value while supporting continuity.
Cost & Risk Optimization
Balance continuity, cost, and long-term resilience.
Core Elements
Author
Professor Dr. Peter Sandborn
Director, University of Maryland (CALCE)
Lifecycle cost analysis, design refresh planning, obsolescence forecasting, and long-life system sustainment.
01.
What is the main objective of Step 06?
To determine the most effective strategy for maintaining product support when components become unavailable.
02.
When should a Last Time Buy be considered?
When component discontinuation threatens production or service continuity and alternative mitigation approaches are not immediately preferable.
03.
How is an LTB quantity determined?
By evaluating lifecycle demand, service obligations, manufacturing losses, aging effects, regulatory exposure, and inventory availability.
04.
When is redesign preferable to an LTB?
When long-term lifecycle costs, compliance risks, storage costs, or strategic benefits outweigh the value of stockpiling inventory.
05.
What is the Porter Refresh Model?
A lifecycle cost model that helps identify the optimal timing for redesign by balancing increasing LTB costs against decreasing redesign costs.
06.
Why is storage management critical?
Because improperly stored inventory can degrade, become non-compliant, or lose usability before it is needed.
07.
Which standards support this step?
Primarily IEC 62402, SD-22, and associated lifecycle sustainment and inventory management practices.
Frequently Asked Questions
Standards Traceability
Theme
Standard & Clause
LTB / Life of Need Buy Definition & Use
IEC 62402 §10.3 • SD-22 §4.4
Notification Handling (PCN, PDN, NRND)
IEC 62402 §9.2 • SD-22 §3.3
LTB Quantity Calculation & Service Obligations
IEC 62402 §10.3 • SD-22 §4.4
Cost Analysis (NPV, Porter Model)
IEC 62402 §11.2 • SD-22 §4.4
Stockpiling & Storage Requirements
IEC 62402 §10.3, Annex C • SD-22 §4.4
Compliance Monitoring During Storage
IEC 62402 §4.1, §8.10 • SD-22 §4.3
Implementation Guidance
Practical considerations and implementation details for this step.
Step 06 — Last Time Buys & Stockpiling
Securing product continuity when components become unavailable.
Context
Technology and component obsolescence require organizations to make difficult decisions about continuity, cost, and risk. Stockpiling inventory is one option, but often competes with redesign, substitution, or supplier transition strategies.
Effective decision-making balances short-term availability with long-term cost, flexibility, and resilience.