Lesson 2 of 5
Inspection planning basics
9 min
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An inspection is only as good as its plan. Before any lot is created, a quality planner decides what to check, how much to check and what counts as a pass. In SAP S/4HANA that knowledge lives in a few master data objects that the lot copies at creation.
Characteristics
A characteristic is one thing to check. It is either quantitative (a measured value with a target and tolerances) or qualitative (pass/fail, or a code from a catalog). Planners define common characteristics once as master inspection characteristics and reference them in many plans, so a change to the tolerance of, say, shaft diameter is made in one place.
| Characteristic (Contoso example) | Type | Specification | Sampling |
|---|---|---|---|
| Rotor winding resistance | Quantitative | Target value with upper and lower limits in ohms | 5 per lot |
| Shaft diameter | Quantitative | Target with tight tolerances in millimeters | 5 per lot |
| Slip ring surface | Qualitative | Pass / fail with a defect code if rejected | 10% of the lot |
| Packaging and labeling | Qualitative | Pass / fail | 1 per lot |
Illustrative rotor characteristics. Values are examples, not engineering data.
Inspection plans and how a lot finds one
An inspection plan groups characteristics under operations, for example "Visual check" and "Electrical test". When a goods receipt creates a lot, the system looks for a valid plan using the material, plant, lot size and the lot creation date. If more than one plan fits, the technician chooses. For in-process inspection, the characteristics come from the production order's routing instead of a separate inspection plan.
Sampling
Each characteristic has a sampling procedure. It can be a fixed sample (5 rotors), a percentage (10%), a full inspection (100%), or a sampling scheme that scales the sample to the lot size. The lot header shows the largest sample across its characteristics, which tells the warehouse how many pieces to pull. Dynamic modification can reduce or skip inspections after a run of good lots, a topic for the 300-level course.
Sampling is also where QM saves money. SAP Learning describes two levers for goods receipt inspection: an inspection skip for material and supplier combinations where the supplier runs a certified quality system, and dynamic modification, which skips a set number of inspections or reduces the sample after a run of accepted lots and tightens again after a rejection. Both are rules the system applies automatically, so both need test cases: a good history should reduce inspection, and a rejection should bring full inspection back.
Who owns what
Quality planners maintain inspection plans, characteristics and sampling. Application consultants configure inspection types, catalogs and stock posting rules. Inspectors and quality engineers use what the planners built. In a project, put each of these in the RACI: a missing plan at go-live means lots that cannot be inspected and stock that cannot be used.
What would you do?
Engineering widens the tolerance for rotor winding resistance. A lot created yesterday still rejects a rotor that would pass the new tolerance. A tester logs this as a defect. What is your view?
- Inspection plans group characteristics; master inspection characteristics make them reusable.
- Characteristics are quantitative (measured, with tolerances) or qualitative (pass/fail or codes).
- Sampling procedures set how many units are inspected per characteristic.
- Lots copy specifications at creation; master data changes affect only new lots.
Check your understanding · not graded
Lesson check
1. What does a quantitative characteristic record?
2. Where do in-process inspection characteristics usually come from?
3. Who typically maintains inspection plans and sampling?
4. Engineering tightens a rotor tolerance today. Which lots use the new value?