Estimating software for machining: what to check

What should you compare estimating software on?

Comparing screens and licence prices is easy and tells you little. The question that matters is narrower: does the package price a drawing from your shop the way you would, and can you check the result. The table makes that question testable.

Subduxion makes Blake, so this guide is not neutral about Blake. It is neutral about the rest: no brand names, and every point applies to any package, a spreadsheet included.

What kinds of estimating software are there?

Machining shops run into five kinds, and the main difference is where the estimate starts.

A shop with steady repeat work and fixed routings prices well from its ERP. A shop that gets new drawings every week starts at the part. The instant-quote portal starts at the wrong end: at the buyer's upload, with machines, rates and setups that count only as far as the portal knows them. Take such a price as your own and a part that needs a third setup is priced like a part with two, and that difference comes out of your margin. Where a spreadsheet works and where it strains is covered in Excel estimating: where it works, where it strains.

Alongside those five sits a kind on your customer's side: should-cost software for purchasing and engineering. A buyer uses it to work out bottom-up what a part ought to cost, from material, operations, machines and rates. US federal acquisition rules define a should-cost review as a cost analysis that will not take a supplier's past costs as proof of efficiency, and so examines its workforce, methods, materials and equipment directly. With such a model, the buyer can ask at every line of your quote where your time or rate differs.

Does the package work from your drawing and your model?

A request comes in as a STEP model with a PDF drawing. The model carries the shape, the drawing the requirements: tolerances, surface roughness, material, finishing and the threaded holes. A 2016 US report for NIST describes the same practice: many smaller suppliers still get either a fully dimensioned 2D drawing, or a 3D model with the requirements on a separate 2D drawing.

A package that reads only the model is pricing half the request. Even together, model and drawing do not fix the route. Subduxion describes how two capable shops can turn the same drawing into two different plans, both valid, since each has its own machines, tooling and way of setting up. Route, setup time and margin should therefore come from your shop, not from an average inside the package.

In the demo the test is simple: which values come from the drawing, and how do you correct one? A proposal you confirm is a different thing from a value that vanishes into a formula.

Can it price with your own machines and rates?

A cost based on an average set of machines is somebody else's cost. Good estimating software works with your machines: envelope, axes and an hourly rate for each. A 5-axis operation then lands on the 5-axis machine, at that machine's rate.

Fitting the envelope does not make a machine suitable. Each operation also has to be reachable, there has to be tooling for it, the setup has to hold the workpiece and the dimension has to stay within tolerance. That is why Subduxion describes machine selection as a reasoning problem rather than a database lookup.

In the demo, enter a machine from your own floor and see which limit decides: the X travel, the fourth axis or the rate. Building that rate is covered in How do you calculate a machine hour rate?.

Can you check every line?

Two cost engineers pricing the same part often arrive at two prices. That is no disaster if you can see where they part ways. For that you need a cost build-up: material, machining, finishing, setup and programming as separate lines. Each line then carries its line inputs: the time, the rate and the quantity it calculates with.

Ask where each figure comes from. Provenance means the drawing, your catalogue or a colleague, plus who confirmed it. A calculated time should read as an estimate until a measured time stands beside it. Why that label matters is covered in Four cycle times for the same part.

In the same demo, have a quantity break priced at 1, 10 and 50 off. Setup and programming time fall once per batch, while cycle time counts per part. A package showing a lower price per part at 50 should show how much of that comes from the one-off time.

What happens at a new revision or a repeat order?

A customer sends revision C of a drawing you quoted at revision B. One dimension has changed and a hole has been added. In a good package the revision B estimate still sits beside the new one, and you can see which lines the change moves.

A repeat order works the same way: you want last time's cost, quantity and rate. Every quote version that went out should be kept with its estimate and drawing revision. In the demo, ask for the previous version of a quote, not the latest.

How does the quote get into your ERP?

CAD holds the geometry, CAM the machining strategy and the ERP the orders, material and cost. Subduxion's research on the data gap describes how each of those systems holds only part of the picture, and how connecting them still does not explain why a manufacturing engineer chose one route over another. Estimating software sits in between; the question is how the quote gets out without retyping.

Ask two things: your ERP supplier which import it supports, and the software supplier which export it provides, in what format and with which fields. An export to CSV and JSON that your ERP can read is in use sooner than a link still to be built.

Ask about your data in the same conversation: where your drawings and rates are held, who can see them and how you take them with you if you switch. An export you can read yourself is also your way out.

Which promises deserve a closer test?

Subduxion's research separates two steps: finding a hole in the model, and working out what that hole demands of the operation. The second is the hard one. So test above all what the package does after recognition: whether it prices with your own machines and rates, and keeps a correction on record with its reason.

Milling and wire EDM remove material in physically different ways: one with a cutting tool, the other with electrical discharges. Subduxion argues that a single model cannot cover every process in the same way. So ask per process what the package calculates, and how.