HM Treasury

Invest to save budget (ISB)


This is a very quick guidance note on evaluating an Invest to Save Budget (ISB) project. It is not intended to replace guidance put forward by lead departments or the Treasury's guidance on investment and appraisal (the Green Book).

Why do I need to complete an evaluation of the project?

The ISB aims to build an evidence base of what has been effective (or not effective) in improving the delivery of public services. This base depends on knowing how projects performed against their objectives.

One way of looking at the ISB portfolio is as a series of 'experiments', each one investigating a new method in public services delivery. Each 'experiment' is not complete until its results have been evaluated. This evaluation is crucial in deciding whether the project should be sustained by other funding streams or adopted more widely.

Who are the intended audience?

ISB projects attract some fairly wide interest, but there are likely to be three main groups:

Is there a standard format?

There isn't a set format for all ISB projects. Your department may well have a set format that they would like you to follow. Given that a large number of the intended audience will not want to know the full detail of the project, the evaluation should start with an Executive Summary.

What should the evaluation cover?

The evaluation should summarise:

The evaluation should present the all the evidence of the outturn of the ISB project. Wherever possible, this evidence should be presented in numerical form, e.g. savings, reduction in time, improvement in satisfaction.

The evaluation should also point out any other lessons from the project, e.g.

Who should do it/ How much should it cost?

This depends on the size of the project in question and the nature of the evidence available. The only rule is that someone who is not otherwise involved in the project should complete the evaluation. This is to get an 'independent' view. For small projects with simple objectives, it would not be appropriate to hire outside experts to complete this task. In this case it is perfectly acceptable for someone from one of the partner organisations to complete the evaluation, so long as they were not closely connected with the running of the project.

When should we complete the evaluation?

When you are in a good position to judge what the effect of the project has been. This should not be too long after the project has finished. It may be appropriate to conduct an interim evaluation of a project during its duration if there is sufficient evidence of its effect.

Where can I go for more detailed guidance?

The Treasury's green book guidance for investment appraisal contains a chapter on evaluating projects.

Useful documents

Example evaluations

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