The reorder point (ROP) is the stock level that tells the team when to place the next order. Minimum stock is the on-site safety buffer. Reorder point is the trigger used before that buffer is consumed while the replacement part is being sourced or machined. A correct ROP reduces stockout risk without forcing excess inventory on low-consumption parts. ROP calculations should be based on average daily/weekly usage rates during lead times plus the defined safety stock for that component group.
PM-Based Review vs Calendar-Based Purchasing
Buying spare parts on a fixed calendar interval can leave critical items short before the next purchase cycle. ROP should be based on actual replacement history recorded in a tool history card for injection molds so stock levels match verified consumption. The history record should capture install dates, replacement dates, cumulative shot counts, and failure reasons so reorder timing is based on actual part consumption metrics.
This history also helps the team decide whether the mold is still under preventive versus reactive mold maintenance control or already reacting to repeated sub-component failures. ROP parameters should be reviewed jointly by tooling, maintenance, and purchasing roles when replacement histories evolve. When purchasing is tied to actual consumption and replacement records instead of monthly buying cycles, long-lead custom parts and standard alignment components can be safely reordered before on-site stock runs out.
Event-Based Triggers and Process Deviations
Beyond normal shot-count reviews, abnormal production events should trigger an immediate inventory check. Events such as parting-line crashes, side-slide galling, or sudden cooling-seal failures should bypass normal reorder timing rules. Any production issue involving sudden flash increases, dimensional drift, seal leakage, broken custom details, or slide galling must trigger an immediate reorder evaluation.
If the mold starts producing flash or wall-thickness variation outside the approved process window set in your standard process sheet and process window study, the normal reorder cycle should be overridden by an event-based trigger. This trigger starts an immediate maintenance review so replacement custom parts can be approved and machined before delivery risk escalates.
Operational Protocol: Every event-based replacement order must be checked against its mold ID, cavity position, and the latest released drawing revision before machining starts to maintain strict configuration compliance. Any structural tool change must be fed back directly through an active injection molding ECN form, linking physical tool modifications directly to overarching mold validation records before press release.
