Software and Automation ROI. How to Build a Business Case

Quick answer

A business case for software or automation does not start with a savings estimate. It starts with the measured cost of the current process. Then it separates the time and cost the solution can affect from the work that remains. Only then does it compare the benefit with one-time and recurring TCO over 12, 24, and 36 months.

This method does not guarantee ROI. It gives decision-makers one model in which they can inspect the source of every number. You can use our calculator for the current-process inputs. Its result is not a promise of savings.

Measure the cost of the current state

Start with one specific flow. It may be order intake, document checking, or report preparation. Measure affected people, manual hours per person per week, total hourly cost, working weeks, and monthly errors or rework. Total hourly cost is not salary alone. It includes employer cost and directly attributable operating cost under your accounting method.

Eurostat explains that labour cost is broader than wages. Its labour-cost source helps define the input. It does not set your company hourly rate.

C = people × weekly manual hours × hourly cost × working weeks + monthly rework × 12

C is the annual cost of the current process. It is a measured input when it comes from time records, payroll data, and rework records. If time is not yet measured, mark it as an assumption and set a date to confirm it.

Set the addressable share and adoption

Automation rarely removes an entire process. Work may remain for exceptions, approval, or quality control. Addressable share states how much of C the solution can affect technically and operationally. Adoption states how much of that share is actually used in the chosen horizon.

B = C × addressable share × adoption

B is the modelled annual gross benefit. Addressable share and adoption are assumptions until a pilot or operating data confirms them. Do not replace them with a generic percentage from someone else's study.

Record full TCO

One-time TCO includes discovery, design, development, integrations, migration, testing, deployment, training, and company staff time. Recurring TCO includes hosting, licences, monitoring, support, security patches, operational changes, and process-owner work. Those categories differ for custom software, AI automation, and software modernization. Do not estimate them with one rate.

The UK Green Book calls for documented assumptions and sensitivity analysis. Its appraisal guidance is not Rise pricing. It explains why each input needs an owner and a source.

B(H) = B × H / 12
TCO(H) = one-time TCO + recurring monthly TCO × H
ROI(H) = (B(H) - TCO(H)) / TCO(H) × 100
Payback = one-time TCO / (B / 12 - recurring monthly TCO)

H is 12, 24, or 36 months. Payback applies only when its denominator is positive. If monthly benefit does not cover recurring TCO, there is no payback and the scenario is a stop signal.

Use conservative, base, and upside inputs

Do not use invented multipliers. Change only inputs whose reason you can state. A conservative case may use a smaller addressable share, slower adoption, or higher recurring cost. The base case should use the best current evidence. An upside case may use a pilot result, not a marketing promise.

Run sensitivity one variable at a time. Show what happens with lower adoption, higher TCO, or a smaller addressable share. Set stop criteria before work starts. For example, stop after a pilot if the minimum case volume is not confirmed, net monthly benefit remains negative, or a critical integration has no safe operating path.

Keep non-financial risks separate. Security, legality, data quality, supplier dependency, and customer impact matter. Do not assign them a euro value without evidence. Record the risk owner, control, and decision it can trigger.

Worked example without hidden multipliers

A company measures five people, five manual hours per person per week, a €35 total hourly cost, and 46 working weeks. Monthly rework is not documented yet, so it is €0. The base annual cost is €40,250. This is a measurement with the assumption that recorded time represents a normal month.

The team assumes a 60% addressable share and 70% adoption after launch. B is €16,905 per year. One-time TCO is €18,000 and recurring TCO is €350 per month. That gives €22,200 TCO and about -23.9% ROI at 12 months, €26,400 TCO and 28.1% ROI at 24 months, then €30,600 TCO and 65.7% ROI at 36 months. Payback is about 17 months.

The example does not say your project will have this outcome. It shows substituted formulas and separates measured cost from assumptions about addressable work and adoption.

Create internal consensus

Before approval, confirm the following.

• The process owner confirmed the measurement boundary and exceptions.
• Finance confirmed hourly cost and TCO categories.
• Operations confirmed the adoption condition and pilot measurement method.
• Security or the accountable person confirmed open non-financial risks.
• The sponsor approved the minimum result, stop criteria, and date of the next decision.

The model has limits. It does not capture unverified revenue growth, future process change, or value you cannot reasonably measure. If inputs need work, compare them with our pricing, read further decision guides, and book a short consultation block. The next step is to confirm inputs, not defend a project already selected.