A business case for HR technology is stronger when it starts with costs the organisation can already see. That means licence fees, payroll checking, duplicated data entry, reporting work and the time spent fixing records that do not agree. Without that baseline, projected savings are little more than guesses.
This method is for UK HR, payroll and finance teams assessing a replacement or a move from separate systems. By the end, you should have a documented current cost, an estimate of what could change, the full cost of implementation and a return calculation whose assumptions can be checked by finance.
Start with what your organisation spends now. Gather annual licence fees, support charges, integration costs and any separate tools used to move information between HR and payroll.
Then add the work around the technology. Track the time spent entering the same employee change twice, reconciling records before payroll, fixing mismatched reports and answering queries caused by information being out of date in one place.
For your current HR and payroll system, or the separate tools doing that job now, record both cash costs and hours. Do not convert the hours into savings yet. At this stage, a good outcome is a baseline that finance can trace back to invoices, payroll cycles and recorded work rather than estimates from memory.
One mistake is to count only software licences. That can make the current setup look cheaper than it is while hiding the work required to keep it running.
Take one or two recent payroll cycles as a starting sample and follow common employee changes from approval to pay. Before annualising the results, check whether those cycles were typical for your organisation. Salary changes, new starters, changed hours and leavers are useful places to look because they often involve both HR and payroll.
Record every handover. Note where information is typed again, exported, checked against another record or chased by email. When repeated entry is one of the costs you have measured, assess whether payroll built into a cloud HR system could reduce the need to enter approved employee changes again.
Do not count every manual task as removable. Payroll still needs checking, approvals still need owners and some exceptions may still need human attention. The useful output from this step is a list of activities that could reasonably disappear, be reduced or remain unchanged.
Once the hours are known, attach an employment cost to them. Base the calculation on the roles that actually perform the work, using salary and relevant employer costs where reliable figures are available.
Keep two categories separate. Cash savings are reductions in expenditure that your organisation reasonably expects to realise. Redeployed time is different. Saving five hours of payroll administration does not put five hours of salary back into the bank if the employee remains in the same role.
An integrated HR payroll system may reduce repeated checking or entry, but the financial model should say what happens to that time. If it will be used for work that is currently delayed or outsourced, explain that. If the benefit cannot be valued credibly, keep it as a non-cash benefit rather than forcing it into the return calculation.
Next, build the investment side of the calculation. Ask vendors for written figures covering software, implementation, configuration, data migration, training and ongoing support.
Add internal costs too. Payroll, HR, IT and finance may need to review data, test processes or attend training. If old and new systems will run together for a period, include any overlapping licence or service costs.
Data cleaning deserves its own line. Moving duplicate or inaccurate records into new software does not correct them automatically, so allow for the work needed before migration.
A good outcome is a cost schedule that separates one-off implementation costs from recurring costs, with every assumption visible. Avoid hiding internal project time simply because no external invoice will arrive for it.
A single optimistic forecast gives finance very little room to test the case. Build at least a cautious scenario and an expected one using the evidence collected in the earlier steps.
When assessing cloud based HR and payroll software, ask the supplier which parts of your current workflow the proposed setup can actually handle and which still need manual review. Use that information to adjust the hours and costs in each scenario rather than applying a generic savings percentage.
Keep projected error reduction especially conservative. If there is no reliable history showing how much payroll rework costs now, do not invent a future saving for it.
This step should leave you with annual benefits that can be traced back to a measured activity, an avoided contract cost or an assumption clearly labelled as an estimate.
Once the cost and benefit figures are complete, calculate return on investment using a consistent period.
For a simple net return percentage, use
Return on investment = (total benefits minus total costs) divided by total costs × 100
If the project costs £80,000 over the period being assessed and the measured benefits total £100,000, the calculation is
(£100,000 minus £80,000) ÷ £80,000 × 100 = 25%
Do not stop at the percentage. Calculate the payback point separately by tracking when cumulative cash savings overtake cumulative cash costs. Finance may also want to see the annual cash impact separately from time that has been redeployed rather than removed.
Finally, use sensitivity analysis to test the assumptions. Reduce projected time savings, increase implementation costs and see whether the case still makes sense. If a small change turns a positive return into a negative one, the proposal depends heavily on assumptions that need more evidence.
By this point, you should have more than a percentage. You should have a baseline finance can verify, a documented view of which work may change, a full implementation cost and at least two scenarios showing how sensitive the calculation is.
That is the point of the exercise. The return figure may support the investment or show that the case is not strong enough yet. Either result is more useful than beginning with a desired percentage and working backwards to justify it.
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