How do you compare supplier offers on total cost, not unit price?
The cheapest unit price is often not the cheapest offer. Total cost of ownership adds price escalation over the contract term, implementation, internal effort, risk and the cost of leaving. Compare offers over the full term, element by element. Differences outside the price line regularly reverse the ranking.
TCO = Σ annual price (with escalation) + implementation + internal effort + risk cost (probability × impact) + exit cost
Three-year comparison of two offers (€ thousands)| Element | Offer A | Offer B |
|---|
| Year 1 price | 300 | 330 |
| Escalation | +5% per year | Fixed |
| Price over 3 years | 945.75 | 990 |
| Implementation | 120 | 30 |
| Internal effort | 60 | 20 |
| TCO, 3 years | 1,125.75 | 1,040 |
Illustrative figures
Offer A: 300 + 315 + 330.75 = 945.75 in price, plus 180 in implementation and internal effort.
Offer B: 990 in price, plus 50.
Offer B is 10% more expensive in year one and €85,750 cheaper over the term.
Where this decision is actually made
A TCO comparison is a model of the future, not a record of the past, which is why it rarely comes out of spend analytics tools such as Sievo: they analyse historical spend extracted from ERP and P2P systems. Comparing offers before award works from the parameters of the offers themselves. That forward-looking comparison is the task of scenario-based procurement analytics.
Which costs are most often missing from a comparison?
Three groups recur. The first is escalation: indexation and escalation clauses applied over the full term, not only to the first year’s price. The second is the cost of getting started — implementation, integration, training and the internal time spent by your own staff, which rarely appears on any invoice.
The third is the end of the contract and its conditions: exit and migration costs when the term ends, minimum volume commitments that must be paid whether or not the volume is used, and payment terms that change the cash position. Each of these can be stated as an amount and added to the comparison.
How do you put a number on risk?
List the risk events that matter for the purchase — a delivery delay, a quality failure, the supplier leaving the market — and for each one multiply an estimated probability by its financial impact. The result is an expected cost that can sit in the same table as price and implementation.
Rough estimates are better than a qualitative note, because they make offers comparable: a remark that one supplier is “higher risk” cannot be weighed against a price difference, while an expected cost can. Apply the same risk events to every offer, so that differences in the total come from the offers and not from the way each was assessed.
Should future costs be discounted?
Over a three-year term the effect of discounting is usually small, unless the amounts involved or the interest rates are large. For a short comparison, undiscounted totals are normally enough to rank the offers.
For terms of five years or more, apply the company’s discount rate, because costs that fall late in the term weigh noticeably less in present-value terms than costs paid at the start. An offer with high implementation costs and low later prices is affected differently from one with the reverse profile. Whatever the choice, apply it identically to every offer.