When a repeat order changes, compare the editable source, CAM operations, tools, post, setup, and output—not just the file timestamp. A controlled diff should show what changed, why it changed, and which checks must be repeated before recutting.
Identify the Released Baseline
Give every released toolpath a revision identity tied to the source model and setup. File timestamps and names such as ‘final2’ are not enough when a repeat order can be cut months later. Record the reason for change so the reviewer knows which dimensions, tools, or process assumptions should differ.
Separate Design Changes From Manufacturing Changes
Use a geometric comparison before looking at cycle time. Overlay boundaries, stock, origins, fixtures, and toolpaths; check missing operations, changed depth, reversed compensation, altered entry points, and regions newly exposed to the holder. A small CAD edit can regenerate motion far beyond the edited feature.
Compare Toolpaths by Material Removed
Compare setup and tool data separately from path shape. Tool library diameter, flute length, holder, projection, spindle command, feed, stepdown, allowance, and work offset can change while the colored line looks similar. Include post-processor and machine-profile revisions in the review. A revision that changes approach, retract, or holder clearance should reopen the checks in What a CAM Collision Check Must Include Beyond the Tool.
Revalidate Dependencies That Did Not Visibly Change
Backplot or simulate both posted files from the same stock state where possible. Compare extents, retract heights, tool changes, total distance, and estimated time. Treat a large unexplained time reduction as a reason to inspect for omitted work rather than an automatic improvement.
Run a Controlled First Article
Run a first article when the revision can affect fit, safety, fixture clearance, or appearance. Measure the features named in the change request plus stable reference features that should not move. This distinguishes an intended edit from an unintended shift in scale, origin, or setup.
Archive the Superseded and Released Packages
Archive the superseded and released files with source revision, post version, comparison record, approval, and inspection. Operators should receive only the released file in the production location, while old versions remain traceable but cannot be selected accidentally.
