The stakes of getting shelf life wrong
In aerospace and defence manufacturing, composite materials — prepregs, adhesives, structural resins — are not shelf-stable commodities. Each roll of carbon fibre prepreg carries a manufacturer-certified out-life measured in days, not months. Each batch of structural adhesive has a thaw cycle budget. Use a material after its certified life expires, and you have introduced an unqualified constituent into a safety-critical structure. The consequences range from a scrapped airframe section to, in the worst case, a structural failure in service.
A top engineering conglomerate, a major manufacturer of defence aerospace platforms, was running these risks at scale. The organisation managed hundreds of composite material lots simultaneously across cold stores, layup areas, autoclave bays, and intermediate holding zones. Material moved through multiple hands and multiple buildings. The record-keeping was largely paper-based — individual log cards attached to each roll, manually updated as the material moved, with no centralised view of the factory's shelf-life position at any point in time.
The failure modes were predictable: cards detached from rolls, cumulative out-time calculations drifted, near-expiry material sat at the back of a cold store while newer material was consumed from the front. Quality audits revealed recurring instances of materials issued to layup that had exceeded their certified out-life, caught only at final inspection. The corrective action — scrapping the layup and re-doing the work — was expensive. But the more serious concern was the material that passed inspection without the discrepancy being caught.
What the system needed to do
The solution architecture was built around three non-negotiable requirements. First, every material lot had to carry a machine-readable identity from the moment it entered the stores — not from when someone remembered to tag it. Second, every movement event had to update a central time-of-out-of-cold-store record automatically, with cumulative out-time calculated in real time. Third, the system had to prevent issuance of any material whose remaining life was insufficient to complete the planned operation, flagging it before it left the stores counter.
FlowTrack's material control module, deployed as a web portal with companion handheld terminals, provided the tracking backbone. Barcode labels were generated and affixed at goods receipt — each label encoding the lot number, material type, batch date, manufacturer's certified shelf life, and the date of entry into the facility's cold store. From that point, every subsequent movement was a scan event.
Cold-chain management and thaw cycle tracking
The most operationally complex aspect of composite material management is not total shelf life — it is thaw cycle tracking. A roll removed from cold storage must be allowed to reach ambient temperature before use, or condensation will contaminate the resin surface. Each thaw event consumes a portion of the material's certified out-life. If a roll is returned to cold storage and later re-issued, the system must recall every prior out-of-store period and sum them accurately.
The FlowTrack system maintained a continuous out-time log for every lot. Each scan at a cold store exit door recorded a timestamp. Each scan at a cold store entry recorded the return time. The cumulative out-time was displayed on every screen where that lot appeared. When a stores officer attempted to issue a lot, the system performed a real-time check:
- Remaining certified shelf life (from manufacture date)
- Remaining out-life (cumulative out-time subtracted from certified out-life budget)
- Minimum life required to complete the operation as specified on the works order
If the lot failed any of these checks, issuance was blocked. The officer received a specific reason — not a generic error — and the system proposed alternative lots with sufficient remaining life, sorted by FIFO order to prevent unnecessary wastage.
The system's full-kit module was particularly valuable for composite layup operations, where a single component might require seven different material types, each with its own shelf-life constraints. The BOQ-based picking logic ensured that a complete kit was only assembled when every constituent had sufficient life to complete the planned cure cycle — not just sufficient life at the time of issue.
Integration with the ERP layer
The organisation ran BaaN/Infor ERP for financial inventory and production order management. Every material transaction in FlowTrack — receipt, transfer, issue, return, scrap — was synchronised to BaaN in real time via a bidirectional integration layer. This meant the ERP always reflected actual physical inventory positions, including the shelf-life-adjusted usable quantity.
A material lot that had expired was immediately marked as non-conforming in both systems. It could not be issued, could not be counted as available inventory, and appeared on the daily non-conformance report for disposition by the quality team. The ERP's material requirements planning engine could therefore plan accurately against genuinely usable stock rather than nominal inventory that included expired or near-expired lots.
IMO-based real-time status and results
The IMO (Inventory Movement and Observation) control module gave production planners and quality engineers a live view of every material lot in the facility — its current location, current status, cumulative out-time, and remaining life displayed as a colour-coded indicator. Lots approaching expiry turned amber at 20% remaining life and red at 10%. The dashboard required no manual refresh; it updated on every scan event across all handheld terminals on the factory floor.
The outcomes after full deployment were straightforward to measure. The quality team confirmed zero instances of expired material being used in production in the twelve months following go-live — a record that had not previously been achieved. FIFO enforcement, now automatic rather than dependent on stores officer discipline, reduced material wastage by eliminating the scenario where newer stock was consumed while older stock sat untracked in a corner of the cold store. Every material lot now carried a complete audit trail from receipt to consumption or disposition — a traceability record that satisfied both internal quality audits and external airworthiness authority inspections without any additional documentation effort.
Performance measurement against material consumption targets also became straightforward: the system's cost measurement module tracked actual versus planned material usage per works order, enabling the engineering team to identify layup operations with consistently high scrap rates and address the root causes at the process level rather than discovering the problem at final inspection.