MM / P2Pintermediate

MM Physical Inventory Part 3: Periodic, Continuous and Sampling Methods

Key takeaway

Choose the counting method: periodic (all stock at a key date, often year-end), continuous (throughout the year), cycle counting, and inventory sampling (statistical sample extrapolated to the whole stock) — with audit acceptance, effort and business impact.

Explanation

📌 KEY POINTS
✅ Periodic inventory counts all stock at a key date — simple but often requires shutdown.
✅ Continuous inventory counts every item at least once a year while operations continue.
✅ Cycle counting varies frequency by material importance.
✅ Inventory sampling counts a statistical sample and extrapolates if accuracy meets thresholds (auditor agreement needed).
⚠️ Choosing a method without auditor alignment risks year-end rejection.

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▶ WHERE WE ARE
Part 2 covered cycle counting. Now method choice.

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▶ 1. PERIODIC

Key date, all materials; shutdown or cut-off.

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▶ 2. CONTINUOUS

Spread counts across year; warehouse-level (WM/EWM bin counts).

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▶ 3. CYCLE COUNTING

Frequency by indicator.

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▶ 4. SAMPLING

Statistical selection; if sample accuracy is good, results extrapolated.

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▶ 5. SELECTION CRITERIA

Audit requirements, warehouse volume, systems (EWM), cost of shutdown.

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▶ STEP BY STEP

List audit requirements.
Compare effort and disruption per method.
Choose method per plant/warehouse.

✅ CHECKPOINT: the chosen method is documented and accepted by auditors.

Code example

ABAP Code

===== STEP 1: comparison =====Periodic: all items, key date, shutdown | Continuous: all items over year, no shutdownCycle: frequency by class | Sampling: statistical sample + extrapolation ===== STEP 2: tools =====Standard MI transactions | cycle counting MICN | inventory sampling functions (per release) | EWM physical inventory in warehouse

Real project scenario

A high-volume warehouse shut down for two days every year-end for a full count. Moving to continuous inventory in EWM plus cycle counting for high-value items, agreed with auditors, removed the shutdown while keeping accuracy.

Common mistakes

No auditor alignment.
Periodic counts in high-volume warehouses by default.
Sampling without statistics knowledge.
Mixing methods without documentation.
No accuracy measurement.

Best practices

Align with auditors early.
Match method to warehouse.
Document procedures.
Measure accuracy.
Use EWM capabilities where present.

Interview angle

Questions: "Which physical inventory methods exist?", "When use sampling?", "How to avoid year-end shutdown?"
Strong answer: periodic, continuous, cycle, sampling with pros/cons, auditor acceptance, selection criteria.

Practice this lesson

Quick check

1. A high-volume warehouse shuts down for two days every year-end to count. Which approach avoids this?

2. If a physical inventory count for a storage bin comes back as zero quantity, but the book quantity for that material was greater than zero, what is the resulting outcome once the difference is posted?

3. What is a key characteristic of the sample-based physical inventory procedure compared to a full physical inventory?

Interview questions

1. Auditors want accurate year-end inventory, but operations can't shut the warehouse. Which physical inventory method do you recommend?

Answer it in your own words first, then compare.

2. During period-end physical inventory count, a warehouse team reports significant book-to-physical variances for a high-value material. As the MM consultant, how would you approach investigating and resolving the discrepancy before the count is finalized in the system?