Economic models

Every test comes with an economic model in Excel. The test measures how models behave on the task. The economic model works out what that behaviour is worth to a particular firm, by adding the firm's own figures to the test results.

• Test results are fixed inputs. Money wrong, worst run, errors found, false alarms and cost per task come straight from the test and sit on their own sheet.
• The firm adds its own figures, such as volumes, staff cost, review and checking time, how much of a missed error becomes a real loss, and build and upkeep cost.
• Full cost per task is model cost plus checking or review, plus the cost of the mistakes that still get through. Each model runs the cheapest way the firm's controls allow: a model whose results fall outside a set tolerance must be checked.
• Outputs are cost per task, annual cost, saving against the current process, payback on the build, and scenarios such as higher volume, a price change or a bad month.
• A sample of models, chosen to show how far model choice moves the economics. When a new model is tested, it is one more row in the same workbook.

The models for Test 1, reading card statements and Test 2, reconciliation are available on request. Defaults are filled in for an illustrative firm and should be replaced with a firm's own figures.