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The project management triangle — speed, quality, cost — applies to engineering design decisions as much as it does to project schedules. A structured trade-off analysis makes the implicit explicit, prevents decisions by default, and gives teams a shared basis for revisiting choices when conditions change.
The purchase price of a component or system is often the smallest part of what it will cost over its life. Lifecycle cost analysis (LCA) accounts for acquisition, operation, maintenance, downtime, and disposal — revealing total cost of ownership and enabling comparisons that unit price alone cannot make.
Material selection determines performance, cost, and supply reliability for the life of a product. The right method is systematic: define requirements as measurable performance indices, screen by function, rank by cost and availability, then verify against the full specification.
When GE's Lawrence Miles introduced value engineering in the 1940s, he was solving a supply crisis: wartime material shortages forced engineers to substitute components, and many substitutions turned out to work just as well or better at lower cost. Miles's insight was that most engineering cost isn't in the function itself — it's in the way the function is currently implemented. Strip the design back to what it must do, then find cheaper ways to do it, and you consistently uncover 20–40% cost savings without removing a single customer requirement.
This post introduces the value engineering methodology, shows how function analysis guides cost reduction, and walks through the techniques that deliver results in practice. It opens Series 3: Engineering Economics — a series about making smarter decisions at the design stage, before cost is locked in.
The Value Equation
Value = Function / Cost. When value decreases, either the function dropped or the cost increased. Value engineering seeks to restore or increase value by maintaining function while reducing cost — or by improving function without increasing cost.
Value engineering (VE) is a systematic, function-oriented approach to improving product value. It is distinct from cost-cutting in one critical way: cost-cutting removes resources without examining function and often removes value along with cost. VE preserves or improves function while reducing the cost of delivering that function.
Three core questions drive every VE study:
The first question sounds trivial. It is not. Most engineering teams can describe how a component works but struggle to articulate precisely what function it performs for the customer. Separating function from form is the fundamental intellectual shift that makes VE work.
Value Engineering is distinct from Value Analysis (VA), though the terms are often used interchangeably. Strictly, VE applies to designs in progress (pre-production), while VA applies to existing products or purchased components. The methodology is identical; the timing differs.
VE is most powerful when applied early. At 20–30% design completion, most decisions are still open and changes are inexpensive. At 80% completion, cost is largely locked in — tooling has been quoted, supplier relationships are in place, and redesign carries schedule risk. Studies consistently show that the cost influence curve drops sharply after concept phase; VE done late returns a fraction of what early-stage VE returns.
The SAVE (Society of American Value Engineers) framework defines the VE job plan in five phases: information gathering, function analysis, creative alternatives, evaluation, and implementation. In practice, these compress into a structured workshop sequence.
Every component or system performs functions. Functions are expressed as verb-noun pairs — action plus object. The noun is always a measurable parameter.
Examples:
Functions are classified as basic (the primary reason the component exists) or secondary (supporting functions that arise from the chosen design approach). Secondary functions are the first VE target — they are often over-engineered or can be eliminated entirely with a different design approach.
A motor mounting bracket might have basic function: "transmit load". Secondary functions might include: "resist bending moment", "locate component", "provide assembly access", and "accommodate thermal expansion". Each secondary function represents cost. Each represents an opportunity.
Once functions are defined, they are mapped to cost. The Function-Cost matrix allocates the total part cost across its functions. If the bracket costs $18.00 to manufacture and the basic function (transmit load) only consumes $6.00 worth of material and operations — with $12.00 going to secondary functions — then $12.00 is the VE opportunity.
The Function Analysis System Technique (FAST) diagram extends this by connecting functions hierarchically. Starting from the basic function and asking "How?" drills down to sub-functions. Starting from any function and asking "Why?" traces back up to the basic function. Any function that sits far from the basic function path is a candidate for elimination or simplification.
The goal of function analysis is not a perfect academic model — it is a structured way to make cost-opportunity visible to the whole team. A function-cost matrix that takes 90 minutes to build can reveal $20,000 per year in savings that no individual team member would have found alone.
Once functions and their costs are mapped, several techniques generate cost-reduction alternatives:
Tolerance review: Tighter tolerances cost money at every step — more machine passes, more inspection, higher scrap rate. Review every tolerance on the drawing. Is it required by function, or was it specified by habit? Many tolerances are copied from prior designs without analysis. The question to ask is: what is the worst case if this tolerance is relaxed by a factor of two?
Material substitution: If the basic function is structural, can a lighter or cheaper material perform the same function? Aluminium for steel often reduces machining time enough to offset the higher raw material cost per kilogram. In some bracket and enclosure applications, the change from steel to 6061-T6 aluminium reduces total part cost even though aluminium is priced higher per kilogram — because fewer kilograms are needed and cycle time drops.
Parts consolidation: Two parts performing related functions can often be redesigned as one. Each eliminated fastener, weld seam, or mating surface reduces assembly time, tolerance stack-up, and part count. A useful rule of thumb: every eliminated part saves more than its unit cost in assembly and supply chain overhead.
Standard components: Custom-designed fasteners, brackets, and connectors almost always cost more than catalogue equivalents. Before designing a custom retention feature, check whether a standard retaining ring, circlip, or press-fit insert does the same job. Standard components also improve lead time and reduce supply risk.
Process change: A machined pocket can sometimes be replaced with a formed feature. A welded assembly can become a single stamping. Changing the manufacturing process can reduce operations, eliminate fixturing costs, and reduce cycle time — often with a capital investment that pays back in under a year at moderate volumes.
VE Is Not Cost-Cutting
Removing function that customers need destroys value, not just cost. Always validate that required functions are preserved after every VE change. The test is simple: does the revised design still satisfy every requirement in the specification?
Consider a steel motor mounting bracket. The original design is a welded assembly: two laser-cut plates welded to a base, with six tapped holes and a powder coat finish. The cost breakdown is $8.40 in raw material, $6.20 in laser cutting and forming, $4.80 in welding and grinding, $2.10 in tapping and drilling, and $1.90 in finishing. Total: $23.40 per part.
Function analysis identifies the basic function as "support motor" and the secondary functions as "distribute load", "locate motor", and "resist vibration". Ninety percent of the cost sits in structure and secondary functions — a clear VE signal.
Three alternatives are generated:
Option A: Single-piece CNC-bent sheet metal with two self-clinching inserts instead of tapped holes, and e-coat instead of powder coat. Estimated cost: $14.80. No tooling required; achievable immediately.
Option B: Die-cast aluminium, two machining operations, self-tapping screws. Estimated cost: $11.20 at 500 or more units per year. Tooling cost: $9,500.
Option C: Extruded aluminium profile cut to length and drilled. Cost: $9.40 at any volume, but requires redesigning the motor interface flange.
At 200 units per year, Option A is chosen: no tooling investment, 37% cost reduction, all function requirements preserved. At 1,000 units per year, Option B's tooling amortises in fewer than nine months, making it the preferred long-term solution. The VE exercise takes one afternoon and yields a clear, staged cost roadmap.
A contract manufacturer producing industrial enclosures for automation panels ran a VE workshop on a recurring part — an electronics module housing made from die-cast aluminium with 14 fasteners, two mating surfaces, and six surface finish requirements. Unit cost was $54.20.
Function analysis revealed that the basic functions were "protect electronics" and "mount assembly", and that secondary functions were dominating the cost. Specifically: the IP65 sealing requirement on the cover was inherited from a previous product that required it — the current application was IP40. Eight of the 14 fasteners were there because the original designer was unsure of the load and added safety margin without re-examining the fastener count. Three of the six finish requirements applied only to an internal surface no customer ever saw.
Revised design: sheet metal housing with four quick-release captive fasteners, a single external finish, and IP40 cable glands. Unit cost dropped to $29.80. Assembly time decreased by 55 seconds per unit. At 800 units per year, the saving was $19,520 annually — recurring.
The workshop took half a day. The engineering change took three days. The payback period was under two weeks.
When to Run VE
Value engineering delivers the most savings at 20–30% design completion. You have enough detail to analyse functions but changes are still inexpensive. At 70% completion, design decisions are largely locked and VE savings potential drops sharply.
Involve suppliers in VE workshops. Suppliers know their process cost drivers better than any designer. A two-hour workshop with your machining supplier will surface opportunities no internal team would find alone. Suppliers benefit from lower-cost designs too — it improves their competitiveness and often results in better pricing.
Express functions as verb-noun pairs. If you cannot reduce a function to a clean verb-noun, you do not understand it well enough to analyse it. Take time to define functions precisely before generating alternatives. Vague functions produce vague savings.
Cost every function. Allocating manufacturing cost to functions makes opportunities visible. A component with 80% of its cost in secondary functions is ripe for VE; a component where 90% of cost is in the basic function has little room. The allocation does not need to be perfect — rough estimates are enough to reveal where to focus.
Document trade-offs. Some VE alternatives reduce cost by accepting lower secondary function performance. Document what was traded and why, so future engineers understand the design intent and do not inadvertently reverse the decision.
Run it regularly, not as a crisis response. Teams that treat VE as a panic measure when margins are under pressure get poor results. Teams that run structured VE reviews at defined design gates build VE into their culture and catch opportunities systematically.
Start with Your Top 10
Identify your ten highest-cost parts. Run a two-hour VE review on each. Focus on secondary functions and over-constrained tolerances. In most product lines, this simple exercise delivers 15–25% of total manufacturing cost savings with minimal engineering investment.
Value engineering reduces cost on components you already design. The next post examines a different question: should you be designing this component at all? Make vs. buy decisions determine whether in-house production or external sourcing delivers more value — and the answer is rarely obvious from unit cost alone.
