How often should a manufacturing schedule be replanned?

Event-driven replanning is the modern standard: the schedule updates whenever something changes that would alter the optimal sequence. A nightly MRP run is too slow for any high-mix environment. Continuous replanning prevents the "morning plan vs reality" gap that costs most shops 10–15 percentage points of OTD.

Does dynamic replanning destabilize the floor?

Only if implemented badly. A good dynamic replanner uses stability constraints: jobs in setup or in-process are not moved, sequence changes require a measurable benefit, and planners can lock specific operations. The result is a schedule that adapts to reality without thrashing.

What events should trigger a replan?

Machine down or back up, operation complete (especially early or late finish), scrap event, material receipt, hot job insertion, ECO release, operator call-off, shift change, and outside-processing receipt. Each event invalidates a different slice of the schedule; a good engine recomputes only what changed.

Dynamic Replanning — Manufacturing Scheduling Glossary

Definition

Dynamic replanning is the continuous recalculation of the production schedule whenever a relevant floor event occurs — a machine goes down, a job finishes early, material arrives late, an operator calls off, or a hot job is inserted. Instead of regenerating the plan once per shift, the scheduling engine treats the schedule as live and updates priorities and sequences in near real time.

Why it matters

A schedule that is regenerated only nightly is wrong by 9:30 a.m. on a normal day and wrong by 8:15 on a bad one. Without dynamic replanning, planners spend 3–4 hours per day rebuilding sequences in spreadsheets and on whiteboards. With it, the planner reviews exceptions instead of rebuilding the plan, and the floor sees one consistent priority list.

Common failure mode

A spindle goes down on the 7 a.m. shift. The MRP run that produced the schedule was last night. Operators move work to the next available machine by gut feel. By noon, three downstream operations are starved and one hot job is forgotten. The plan in the system no longer matches the plan being executed.

How Skody approaches it

Skody listens for events from the ERP, MES, and operator actions, then replans within seconds. Each replan preserves stability where possible: jobs already in setup are not bumped unless a higher-priority constraint demands it. Planners see the diff, not a brand-new plan.

Schedule Instability

When the schedule changes so often that the floor cannot rely on it.

Finite Capacity Scheduling

Scheduling that respects the real, limited capacity of each machine, operator, and tool.

Production Rerouting

Moving a job from its planned machine or partner to an alternate when conditions change.

Dispatching

Telling each operator and machine which job to run next, in what order, right now.

ERP Snapshot

A point-in-time copy of ERP data used to generate a schedule that goes stale immediately.