For make-to-order manufacturers and job shops, lead time is a competitive weapon. Customers increasingly choose suppliers who can deliver reliably and quickly. Yet in many factories, a part with a few hours of processing takes weeks to deliver. Understanding where that time goes — and removing waiting — is the key to shorter, more reliable lead times.
Where lead time goes
- Order processing: review, quotation conversion, order entry.
- Engineering: drawings, programs, routings, approvals.
- Planning: scheduling and job release.
- Material: procurement and receipt.
- Shop floor: queue, setup, processing, move and wait between operations.
- Subcontract operations: plating, heat treatment and others.
- Inspection and dispatch: final checks, documentation, packing.
In most cases, processing is a small fraction of the total. The rest is waiting.
Measure first
Record timestamps at each stage for a sample of orders. A simple chart showing time per stage for each order reveals where time accumulates. On the shop floor, operation-level tracking shows queue time per operation. See WIP tracking.
Speed up the office
Order entry, engineering and planning can consume days before a job reaches the floor. Standard templates, quicker approvals, reuse of existing programs and routings, and clear handoffs between sales, engineering and planning shorten this stage — often with little cost.
Material readiness
Waiting for material is a major delay. Check material availability at order entry, start procurement immediately for long-lead items, hold stock of common raw materials and agree faster supply with key suppliers. Don't release jobs to the floor until material is available — they will only wait there.
Reduce queue time with WIP limits
Releasing every job to the floor as soon as it's ready creates long queues. Little's Law tells us lead time equals WIP divided by throughput; with throughput fixed, more WIP means longer lead time. Release work based on capacity, especially at the bottleneck, and limit jobs waiting at each operation.
Focus on the bottleneck
The bottleneck determines throughput. Reducing setups, eliminating downtime and preventing starvation at the bottleneck increases throughput, which reduces lead time for everything. See finite capacity scheduling.
Reduce setup times and batch sizes
Large batches make each job wait for the whole batch at every operation. Smaller batches flow faster but need shorter setups. SMED makes smaller batches economical. See SMED.
Overlap operations
Instead of waiting for an entire batch to finish one operation, transfer smaller quantities to the next operation as they're completed. This overlapping can cut lead time significantly for multi-operation jobs.
Manage subcontract operations
Subcontracted processes often add days of waiting. Consolidate shipments smartly, agree turnaround commitments, track jobs out and back and follow up on overdue returns. See job work management.
Streamline inspection and dispatch
Final inspection queues and documentation delays add time at the end. In-process inspection reduces final inspection load; prepared documentation templates and daily dispatch planning keep finished goods moving.
Quoting lead times customers can trust
Shorter lead times only help if customers trust them. When quotations use current load and realistic capacity rather than standard lead times, promises are kept more often. Tracking promised versus actual dates by customer and product shows where promises need adjusting.
An example: a sheet metal job shop
A sheet metal job shop quoted lead times of four weeks, yet processing on most jobs was under two days. Timestamp tracking revealed long waits for engineering programs, material ordered only after release and large queues before welding and powder coating. The shop introduced daily engineering reviews, material checks at order entry, WIP limits at welding and coating, and smaller transfer batches. Within a few months, typical lead time dropped to around two weeks, and on-time delivery improved because fewer jobs were competing for the same resources.
Getting started
Track timestamps for twenty recent orders from receipt to dispatch and chart where time goes. Pick the largest waiting stage and address it first — often material or a shop floor queue — then measure again and move to the next.
Common mistakes
- Focusing only on processing speed.
- Releasing all jobs to the floor immediately.
- Ignoring office and engineering delays.
- Large batches with long setups.
- No measurement of lead time by stage.
How software helps
Planning, MES and WIP tracking software capture timestamps at each stage, show queues and bottlenecks, support WIP limits and realistic scheduling, and track subcontract operations. See production planning and scheduling software.
Talk to us about shortening your lead times.
Lead time segments to track
A simple dashboard by order — days in order processing, engineering, waiting for material, on the floor, at subcontractors and in dispatch — shows managers immediately where the current bottleneck is. As one segment improves, another becomes the largest, and attention moves there. Reviewing this weekly keeps lead time reduction a continuous effort rather than a one-off project.
Frequently asked questions
What makes up manufacturing lead time?
Order processing, engineering and planning, material procurement, queue and wait time on the shop floor, processing time, inspection and dispatch.
Which part of lead time is usually the largest?
In most job shops, waiting — in queues on the floor, for materials, or for approvals — is far larger than actual processing time.
Does reducing batch size help?
Often yes. Smaller batches move through operations faster, though they need shorter setups to remain economical.
How do WIP limits reduce lead time?
By releasing work only when capacity is available, queues shrink and jobs flow faster, as described by Little's Law.
How do we measure lead time accurately?
Record timestamps at each stage — order received, released, each operation, inspection, dispatch — and analyse where time goes.
