Keystone Resource
What precision engineers need from an MRP system
Small batches, repeat work and tight tolerances put pressure on different parts of a system than high-volume production does.
This is a first draft awaiting review by somebody who runs a factory. It is published as a working document rather than as advice.
Most MRP systems were designed around volume. A precision shop making twenty of something to a drawing that has been revised four times is a different problem, and the places a system creaks are different too.
Revision control that is not optional
The question “which revision was this batch made to” should be answerable from the job, not from the date it ran and somebody’s recollection of when the drawing changed.
That means the works order recording the revision, bill and routing it was raised against, rather than pointing at whatever is current.
Costing that survives small batches
Setup dominates a short run. If setup and run are one booking, a batch of twenty and a batch of four hundred look similar per hour and completely different per part, and the quote for next time is wrong.
First article as work, not paperwork
First article inspection takes real time on a real machine with a real inspector. Systems that treat it as a document attached to the job rather than as an operation in the routing will under-plan every new part.
Questions worth asking a vendor
- Does a works order snapshot the bill and routing, or reference them?
- Can setup and run be booked separately against one operation?
- Can I see every job that drew from a particular lot of material?
- What happens to a job in progress when the part is revised?
- Is inspection a routing operation or an attachment?
What this does not cover
Written for subcontract and repeat precision work. A business making its own catalogue products has different priorities, particularly around forecasting.
Next step
Show us how your factory runs
A walkthrough starts with your orders, your production flow and your material problems. We follow one of your jobs through the system rather than presenting a feature list.