Definition
Should-cost modeling: Should-cost modeling is a method of estimating what a product or service should cost to produce or deliver by building up the cost of its components, such as materials, labor, overhead, logistics and a reasonable supplier margin. Buyers compare the estimate with supplier prices to understand the gap and negotiate on facts.
Should-cost modeling is an analytical method for estimating what a product or service ought to cost, based on the inputs required to make or deliver it. Instead of starting from a supplier’s quoted price, a should-cost model builds the cost from the bottom up: materials, labor, equipment and overhead, logistics, yield losses, administrative costs and a reasonable supplier profit margin. Buyers compare the resulting estimate with actual or quoted prices to identify where the gap comes from, then use that fact base to negotiate, challenge price increases or work with suppliers to reduce cost. The approach is sometimes called cost breakdown analysis or clean-sheet costing, although some practitioners use those terms for slightly different levels of detail.
Why should-cost modeling matters
Most price negotiations are anchored on the supplier’s number. Without an independent view of cost, the buyer can only ask for a discount and hope the answer is reasonable. A should-cost model changes the basis of the conversation from “what can you give us?” to “here is what we understand the work requires; help us understand where your cost differs.”
This matters most where competition is limited, where prices are rising or where the supplier relationship is long term. It helps buyers:
- Test whether price increases are justified by actual input cost changes.
- Understand which cost drivers matter most and focus negotiation there.
- Identify design, specification or process changes that reduce cost for both parties.
- Build index-based pricing mechanisms tied to real cost drivers.
- Prepare for sole-source or single-source negotiations where competitive bids are not available.
How should-cost modeling works
The approach is similar for goods and services, even though the inputs differ.
1. Define the scope. Specify exactly what is being costed: the product specification, service scope, volumes, locations and service levels.
2. Map the cost structure. Identify the major cost elements and how the item is produced or delivered. For a manufactured part, that includes materials, process steps, machine time and labor. For a service, it includes roles, hours, shifts and supervision.
3. Estimate each input. Use market data for materials and commodities, published or surveyed wage rates, reasonable productivity assumptions, overhead allocations and freight costs. Document each assumption and its source.
4. Add overhead and margin. Include a reasonable allowance for selling, general and administrative costs and a profit margin appropriate to the industry and risk.
5. Compare and analyze. Compare the modeled cost with the supplier’s price, element by element where possible. The gaps show where to ask questions.
6. Refine with the supplier. Share relevant parts of the analysis and invite the supplier to explain differences. New information often improves the model on both sides.
In words, the core logic is simple: the should-cost equals the sum of all direct and indirect input costs plus a reasonable margin, and the price gap equals the quoted price minus that estimate.
Should-cost vs. related approaches
| Approach | Question it answers | Typical use |
|---|---|---|
| Should-cost modeling | What should this cost based on its inputs? | Significant, repeatable spend with identifiable cost drivers |
| Price benchmarking | How does our price compare with others? | Quick check of market position |
| Competitive bidding | What will the market offer today? | Categories with active competition |
| Total cost of ownership | What does this cost over its full life? | Decisions where acquisition price is only part of the cost |
| Price and cost indexing | How should price move as inputs change? | Long-term contracts exposed to commodity or wage changes |
These approaches are complementary. A should-cost model often informs the index mechanism in a contract, and benchmarking can validate a model’s assumptions.
Common pitfalls
False precision. A model is an estimate. Presenting it as the exact cost undermines credibility when the supplier points out a flawed assumption.
Weak assumptions. Outdated wage data, unrealistic productivity or missing cost elements lead to targets suppliers cannot meet.
Ignoring supplier economics. Suppliers must earn a sustainable margin. Models that squeeze margin to zero damage relationships and service.
Overbuilding. Highly detailed models for low-spend items rarely pay back the effort.
Using it only once. Models are most valuable when maintained and used to govern pricing over the life of a contract.
An example
For example, a hypothetical company receives a price increase request from its contract janitorial provider, citing higher labor costs. The procurement team builds a simple should-cost model using the contracted scope, cleaning hours per site, prevailing local wage rates, payroll taxes and benefits, supplies, supervision and a reasonable margin. The model shows that labor costs have risen, but by less than the requested increase, and that one site is staffed well beyond what its scope requires. The negotiation focuses on those two points, and the outcome is a smaller, documented increase tied to a wage index, plus a revised staffing plan for the over-served site.
How to get started with should-cost modeling
- Choose the right categories, focusing on significant spend, limited competition or rising prices.
- Start simple, with the few cost elements that drive most of the price.
- Document assumptions and sources so the model can be defended and updated.
- Involve technical and operational experts who understand how the product or service is made or delivered.
- Use the model collaboratively to find cost reduction opportunities, not only to challenge price.
- Build it into the contract through index-based adjustments and cost transparency provisions.
How S2V approaches should-cost modeling
S2V uses should-cost modeling where it changes the outcome, not as a default exercise. In the Potential and Priority stages, spend analysis and market intelligence identify categories where price is unexplained, rising or insulated from competition, and the S2V Blueprint decides where a model is worth building. In the Performance stage, Execute builds and uses the models to prepare negotiations and design pricing mechanisms, in categories such as facilities services or packaging.
In the Value stage, the models remain useful after signing. S2V ties price adjustments to the documented cost drivers and tracks realized pricing against them, and through Develop helps client teams learn to build and maintain their own models so the capability stays in the organization.
Related
- Advise — S2V Blueprint
- Execute — S2V Accelerator
- Develop — S2V Academy
- Facilities & Janitorial Services
- Logistics & Freight
- Print, Packaging & Promotional
Frequently asked questions
What is the difference between should-cost and price benchmarking?
Price benchmarking compares what you pay with what others pay or with market prices. Should-cost modeling estimates what the item should cost based on its inputs. Benchmarking shows whether a price is out of line; a should-cost model helps explain why and which cost elements drive the gap.
What goes into a should-cost model?
Typical elements include raw materials, conversion or labor costs, equipment and overhead, packaging, logistics, scrap or yield losses, selling and administrative costs and a reasonable profit margin. Services models focus on labor hours, rates, burden, supervision, equipment and margin.
Can should-cost modeling be used for services?
Yes. For labor-based services, such as janitorial, security or staffing, a model builds up hours, wage rates, benefits and taxes, supervision, supplies and overhead, plus margin. Services models are often simpler than manufacturing models and highly effective.
Is should-cost modeling adversarial toward suppliers?
It does not have to be. Used well, it creates a shared understanding of cost drivers and can reveal ways for both parties to reduce cost, such as design changes, specification changes or more efficient logistics, rather than simply pressuring margin.
When is should-cost modeling not worth the effort?
It adds less value for low-spend or one-off purchases, for highly commoditized items with transparent market prices, or where cost inputs cannot be reasonably estimated. In those cases benchmarking or competitive bidding may be more efficient.