If your team still pushes late-stage changes through email threads and “Final_v27” files, you’re burning money you can’t see.

In complex programmes, the design phase typically “locks in” most of the eventual life-cycle cost; by the time you find issues in verification or production, the price to change can explode by tens to hundreds of times compared to fixing them in design.

According to the NASA Systems Engineering Handbook, around three-quarters of life-cycle cost is effectively committed by design, and the cost to change rises sharply through development, test and operations.

I am an engineer who has worked with customers in the automotive, aerospace and defence manufacturers. I’ve seen parametric, design-intent-driven workflows in SOLIDWORKS cut revision cycles from weeks to hours – without compromising control.

In this article, I’ll show how those results happen in the real world, the change-management moves that make them stick, and what that can mean for your P&L (Profit & Loss).

1. Why late changes are so expensive – and how design intent defuses them

The uncomfortable truth: by the time a drawing hits the shop, many costs are already baked in.

Systems engineering sources consistently note that decisions taken in design commit the majority of downstream cost; push changes later and you pay a steep premium.

What we do about it: encode design intent up front so models behave when requirements move.

• Relations, parameters, and rebuild behaviour. SOLIDWORKS is built to capture design intent so that when a dimension or requirement changes, the model updates predictably.
• Global variables, equations, and design tables. Tying key dimensions to named variables and driving families of parts via configurations/design tables makes controlled change a one-cell update, not a week of re-work.
• Frame workflows. For frames and chassis, standardising weldment/structure-system templates keeps cut-lists consistent across variants – ideal when loads or envelopes shift late in the programme.

In one aerospace tooling project, a late envelope change would previously drive 8–10 days of modelling and drawing churn.

Moving to variables + design tables meant the same change propagated through the assembly in an afternoon, followed by a focused drawing update.

2. Make change controllable: formalise revisions and traceability

Speed without control is just chaos. The second pillar is a robust, visible change path so only the right data reaches manufacturing.

• Versions vs revisions. SOLIDWORKS PDM maintains a complete version history and increments formal revisions when a file passes an approval state – so teams can “work loud” on versions while production only sees the latest released revision.
• Digital change management. On the cloud-based 3DEXPERIENCE platform, Collaborative Industry Innovator and Change Action provide structured issues/changes, approvals, and traceability – closing the loop with audit-ready records.

A defence supplier had recurring production delays from teams building off “almost final” models emailed around.

After introducing PDM states (Work-In-Progress → Review → Released), “Released-only” access on shop PCs, and a simple watermark for working copies, mis-builds dropped to near zero and engineering had the freedom to iterate without contaminating the floor.

Result: fewer scrap incidents and fewer premium-freight expedites.

3. Quantifying the money: two ROI lenses

3.1. Life-cycle perspective (change-order reserve)

According to research in the Journal of Cost Analysis & Parametrics, an empirical study of 1,216 defence contracts found that if Engineering Change Orders (ECOs) occur, 14% (development) and 6% (production) are more realistic rules-of-thumb for reserves than the old 10%/5% figures.

Illustrative calculation (production phase):

• Annual production programme value: R80 million
• ECO (Engineering Change Order) reserve baseline (6%): R4.8 million

If better design-intent and controlled revisions reduce ECO frequency/magnitude by even 20%, this would result in ~R960,000 avoided cost.

This aligns with the principle that changes caught in design are an order of magnitude cheaper than changes in production.

3.2. Engineering-hour and downtime lens (lead-time compression)

Assumptions for illustration (adjust with your rates):

• Loaded engineering rate: R900/hour
• Typical late change before parametric refactor: 2 weeks (~80 hours)
• After parametric workflows: ~4 hours
• Hours saved per change: ~76 (R68,400 saving per change).
• Ten such changes per quarter: R684,000/quarter in engineering time alone – before considering reduced machine downtime or expediting.

Why this works: the NASA cost-to-change curve rises dramatically through the life cycle; pulling changes “left” with parametric modelling and formal change control exploits that cost gradient.

4. What to implement next (the playbook we use with clients)

4.1. Model to change

• Define global variables for key envelopes, interfaces and regulatory dimensions; drive sketches and features from those variables.
• Use design tables/configurations for designs (sizes, options, materials). Lock naming and description rules so BOMs remain intelligible.
• Standardise weldment/structure-system templates and cut-list properties for frames, among others.

4.2. Release only what you mean

• Separate versions (work-in-progress) from revisions (released). Shopfloor devices and purchasing should only see “Released”.
• Automate state changes (Work in Progress → Review → Released) and ensure e-sign approvals are recorded with who/when/why.

4.3. Make impact analysis a habit

Before approving a change, run a structured checklist: affected parts/assemblies, NC/fixtures, supplier PPAPs (Production Part Approval Process), certification knock-ons, spares and service bulletins – using a central change workspace so nothing is missed.

4.4. Measure what matters

Track: ECO lead time, % changes after design freeze, engineering-hours/change, scrap/rework incidents, expedite freight.

Tie the savings to the ECO reserve baseline (Miller et al., 2022) so finance sees the rand value.

5. The Bottom Line

If late-stage changes are normal for you, you’re not just “paying a little extra admin”.

You’re compounding risk on the steepest part of the cost-to-change curve.

According to research and systems-engineering practice, design decisions commit most of your eventual spend, and changes made later cost dramatically more to implement.

The good news: SOLIDWORKS’ parametric tools (design intent, global variables, design tables) and disciplined change control (versions vs revisions, digital approvals, full traceability) let you shift change earlier, control it, and keep production working only to released data.

Our company can help you to streamline your engineering processes.

Should you want more information and help or if you are interested in purchasing SOLIDWORKS PDM to set up these processes, please refer to our PDM QuickStart Implementation service for more information.