SD Availability Check Part 2: Configuring the Classic Availability Check

📌 KEY POINTS
✅ Checking group (OVZ2, material field MTVFP) defines how requirements are recorded (individual or summarized per day/week) and accumulation behavior.
✅ Checking rule identifies the transaction (A sales order, B delivery) and, with the checking group, selects the scope of check.
✅ Requirements class (OVZG) must allow availability check; requirements type (OVZH/OVZI) connects items to the class.
✅ Schedule line category "Availability" flag must be set as well — both levels together switch ATP on.
⚠️ Summarized requirements improve performance but make it hard to see which order holds which quantity; individual requirements do the opposite.

━━━━━━━━━━━━━━━━━━━━
▶ WHERE WE ARE
Part 1 explained ATP. Now the classic configuration objects.

━━━━━━━━━━━━━━━━━━━━
▶ 1. CHECKING GROUP (OVZ2)

• Total sales / total deliveries: A (individual), B (daily), C (weekly) records.
• Accumulation: whether confirmed quantities are considered when rechecking.
• Block quantity required: quantity reserved during entry to avoid double promising.
• No check: skip ATP for this material.

━━━━━━━━━━━━━━━━━━━━
▶ 2. CHECKING RULE

• A: sales order, B: delivery (standard).
• Used with checking group to find the scope of check (Part 3).

━━━━━━━━━━━━━━━━━━━━
▶ 3. REQUIREMENTS TYPE AND CLASS

• OVZI: determination (item category + MRP type, or strategy group).
• OVZH: requirements type → class.
• OVZG: class settings (availability, requirements transfer, allocation).

━━━━━━━━━━━━━━━━━━━━
▶ 4. SCHEDULE LINE CATEGORY

• VOV6 flags "Availability" and "Req./assembly".
• Presales categories switch both off.

━━━━━━━━━━━━━━━━━━━━
▶ 5. PLANT VS STORAGE LOCATION

• Standard: check at plant level.
• If storage location is entered in the order item, check includes that storage location's stock (scope settings apply).
• Storage location-specific MRP areas affect planning, not SD directly.

━━━━━━━━━━━━━━━━━━━━
▶ STEP BY STEP

1. Assign checking group 02 to the material (MM02, Sales: General/Plant or MRP 3).
2. Review OVZ2 settings for 02.
3. Check requirements type/class of the item.
4. Check the schedule line category flags.
5. Create an order and verify ATP ran (Procurement tab / availability screen).

✅ CHECKPOINT: you can switch ATP off for one material by configuration and on again, and explain every object involved.

A client set checking group 01 (daily summarized) for all materials to reduce table load. When customer service had to explain which orders held stock for a scarce product, nobody could see it quickly, and backorder decisions were made blind. For the 400 scarce and high-value materials the team switched to individual requirements (02), kept summarized for the long tail, and documented the rule in the material master governance.

• Setting ATP flags only on one level (schedule line or requirements class).
• Using "no check" checking groups for materials that are actually scarce.
• Summarized requirements for materials needing order-level allocation decisions.
• Forgetting block quantity for high-volume parallel order entry.
• Confusing checking group with MRP settings.

• Choose checking groups by material behavior (scarce vs abundant).
• Keep requirements class and schedule line flags aligned.
• Document checking group rules in material governance.
• Test ATP on and off per material.
• Use individual requirements where allocation transparency matters.

Questions: "What is a checking group?", "What controls whether ATP runs?", "Difference between individual and summarized requirements?"
Strong answer: checking group in material (OVZ2) with requirements recording and accumulation; checking rule A/B; requirements type/class (OVZI/OVZH/OVZG) plus schedule line category flag switch ATP; individual requirements give order-level transparency, summarized improve performance.