Compare complete operating costs

Define the boundary of the calculation

Compare two ways to deliver the same capability at the required quality. A lightweight prototype and a maintained enterprise delivery system are different purchases. Their cost figures are not directly interchangeable.

Choose a period and record what it includes. Separate setup from recurring work. Include people, infrastructure, model use, support, integration maintenance, and the work needed to keep controls effective.

FinOps connects technology spending with accountable decisions and business value. Use that discipline to identify cost owners and explain assumptions. It does not supply a universal build-versus-buy answer. FinOps Framework.

Include retained work in both options

Building an internal system requires more than its initial implementation. Someone must maintain orchestration, model integrations, evaluation, platform interfaces, security controls, and documentation. Count support and upgrade work after launch.

Buying a service also leaves work. Product ownership, data decisions, integration, review, and incident coordination can remain internal. Use the responsibility map to identify this work rather than assuming that the subscription replaces the whole team.

Estimate full-time equivalents rather than assigning every part-time responsibility to a separate person. Avoid counting the same work twice. Use the organization’s actual fully loaded cost where available.

Work through a fictional comparison

The following amounts are illustrative. They are not Taiga prices, market benchmarks, or customer results. Both options use a fictional annual person cost of €120,000.

The calculation is setup plus three years of recurring cost. The buy option is €210,000 lower under these assumptions.

Now increase retained work to 1.5 people and the subscription to €150,000. The buy total becomes €1,140,000. The build total remains €1,080,000. Two changed assumptions reverse the cost ordering.

Try these changes in the interactive calculator. The exercise shows sensitivity, not the correct price for your organization.

Keep omitted effects visible

The simple calculator excludes discounting, taxes, inflation, transition delays, and exit costs. Add them to a decision model when they are material. A finance owner can help choose the organization’s required method.

Also compare time to a usable outcome and the value of the alternative work your team could perform. Keep uncertain benefits separate from verified cost inputs. Do not manufacture precision by assigning unsupported savings to every generated line.

Check whether the options meet mandatory requirements before treating price as decisive. An inexpensive option that cannot support the required data boundary is not equivalent to one that can.

Record a range and a review trigger

For uncertain inputs, use a low, expected, and high case with reasons. Identify the assumptions that change the decision. Request evidence for those first, such as integration effort or retained operational work.

Record when you will revisit the model. Contract changes, adoption across more teams, and new platform requirements can alter the result. The calculation should support an accountable decision that can be updated.