A Factory Acceptance Test (FAT) at the builder’s premises and a Site Acceptance Test (SAT) at the installation may use different materials, utilities and operators. Machine manufacturers should agree the conditions with the customer before comparing results. If OEE forms part of the assessment, define its calculation basis in the test plan.
1. Separate acceptance criteria from OEE
Overall Equipment Effectiveness (OEE) combines availability, performance and quality. It does not cover every safety check or contractual requirement for accepting a machine.
Define the test purpose
Agree the product, materials, machine configuration, test run and acceptance criteria for each item. Identify the witness and approval responsibility.
Define comparable data
Record planned production time, the fastest achievable time per unit under the agreed conditions (Ideal Cycle Time), and good-part criteria. Parts requiring rework should not be counted as first-pass good output.
Sources: [1]
2. Retain changes between FAT and SAT
Siemens’ 2026 discussion of machine lifecycle data highlights continuity from development to use. For acceptance work, keep the conditions of each test traceable rather than relying on the final score alone.
Keep each test baseline
Link results to the machine identifier, software revision, material and settings that the responsible people have authorised for recording.
Separate retest causes
Distinguish machine faults, missing data, site conditions and changed requirements. A repeated test is not automatically evidence of machine failure.
Sources: [2]
3. Trial the records before acceptance day
Compare system counts and timestamps with shop-floor records during a trial run before the acceptance appointment. This exposes inconsistent definitions while the plan can still be corrected.
Include exceptions
Test material waiting time, reworked parts and stops with no reason code. Check whether both teams classify the same events consistently.
Track repeated work
Measure retests caused by incomplete evidence and the hours needed to prepare records. Compare them after changing the recording procedure.
Frequently asked questions
How should the acceptance OEE target be set?
Start with the product and conditions being tested. Agree the time basis, counting rules and target for that job rather than applying one percentage to every machine.
Which records should be trialled before acceptance?
Compare the test plan, signal list, sample counts and stop records. Also identify the acceptance documents and signing responsibilities that the project requires.
Prepare production evidence for machine acceptance
Explore DigitechX OEE with a test plan, sample counter data and good-part criteria to assess how the machine’s results should be recorded.
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References
Information and sources reviewed: 9 October 2026