Industrial Software Integration & APIs worked example

Integration Test Workload at 40% retest and regression allowance: a worked example

This scenario runs the integration test workload calculation on the strong side: 40% retest and regression allowance, with every other input held at its documented default. Use this calculator when planning QA resources for integration testing phases, estimating UAT effort for ERP/MES connections, or scheduling test cycles before go-live.

The inputs for this scenario

  • Test cases to execute: 120 test cases (unchanged)
  • Test execution rate: 4 cases / hour (unchanged)
  • Retest and regression allowance: 40 % (raised for this scenario; the documented default is 35)

Working through the calculation

  • Applying the documented formula (Base test execution hours = test cases / test execution rate) to the inputs above produces each figure below.
  • At this operating point the engine returns 42 hr for total integration test hours, the number this scenario is built around.
  • At this operating point the engine returns 30 hr for base test execution hours.
  • At this operating point the engine returns 40 % for retest and regression hours added.
  • At this operating point the engine returns 4 pieces / min for test execution rate (cases/hour).

How this compares with the baseline

  • Against the tool's baseline example, where retest and regression allowance sits at 35% and the headline result is 40.5 hr, this scenario comes in 3.7% above the baseline at 42 hr.
  • Use it during test planning for any system-to-system integration — API contract testing, EDI/B2B onboarding, MES-to-ERP interfaces — before you lock a test window or quote a fixed-price test phase. Treat this as a target state: the delta against the baseline quantifies what the improvement is worth before you commit to chasing it.

Results at a glance

  • Total integration test hours: 42 hr (headline result)
  • Base test execution hours: 30 hr
  • Retest and regression hours added: 40 %
  • Test execution rate (cases/hour): 4 pieces / min

Run it with your numbers

  • Every input above is editable in the live Integration Test Workload calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.