Unit 4: Reservations

Lesson 1 · Creating Manual Reservations

Key concepts

A reservation is a requirement placed on the warehouse to provide material for a later movement – usually a withdrawal – for a specific purpose. Because MRP sees it as a requirement, the material can be procured in time; and because it already contains material, quantity, plant and account assignment, the later goods issue is quick to enter and the issuing department can prepare picking.

Reservations mainly plan goods issues and transfer postings; transfer postings can only be planned for the one-step procedures 311 (storage location to storage location) and 301 (plant to plant). Receipt reservations (e.g. 501) are possible but only sensible in exceptions – when Purchasing and Production are in use, receipts are planned by POs and production orders.

Structure

Header: creator, movement type, account assignment (cost center, order, WBS…), base date. Items: material, quantity, requirement date, plant, storage location, Movement Allowed and Final Issue indicators. A reservation has exactly one purpose – one movement type and one account assignment – and these cannot be changed after saving. Mandatory data for creating a GI reservation: base date, movement type, plant, material, quantity, plus account assignment depending on the movement type (storage location is not mandatory).

Tools

Goods movement with reference to a reservation

• Only items with the Movement Allowed indicator can be referenced, and the MIGO search finds only these. Leaving it unset blocks premature withdrawals for far-future requirements. Whether it is proposed is set per plant (OMBN); it can be toggled for all items (Edit › Other Functions › For All Items › Movement In/Out) or set in mass by MBVR.
• Reference is always at item level.
• Final Issue is set automatically when the full quantity has been withdrawn, or manually (at goods movement or by changing the reservation) when a partial quantity suffices.

Process flow

System steps

1. MB21: base date, movement type (e.g. 201), plant; Enter.
2. Enter cost center (account assignment) and items with material, quantity, storage location, requirement date; save.
3. MIGO: Goods Issue + Reservation; enter number; copy items; set OK; post.

Configuration (IMG)

Lesson 2 · Evaluating Reservations

Key concepts

Reservation list (MB25)

Select by material, requirement date, creator, goods recipient or account assignment. The ALV output lists items with reservation number/item, material, required quantity, movement type, account assignment, requirement date and the open difference quantity; receipt reservations appear highlighted in yellow. Layouts can be adjusted; double-click opens the reservation or item.

Reservation management (MBVR)

Mass maintenance of manual reservations. The base date plays two roles: it selects reservations whose header base date is ≤ the entered date, and it is the starting point for calculating key dates.

Default values per plant (OMBN)

• Propose Movement Allowed at creation
• Days for setting Movement Allowed in MBVR
• Retention days for deletion in MBVR
• Automatic creation of storage location data when posting a reservation (also requires activation for plant and movement type)

Picking list (MB26)

Posts goods movements for several reservations (and production orders) in one step. Select by reservation, material, account assignment or production order. Before posting you can adjust quantities, set Final Issue, enter storage locations, call stock determination (Goto) or batch determination (Environment › Batch Management), split items (Edit › Splitting), sort and filter. Caution: filtered-out items are still posted – remove unwanted items with Edit › Delete. A printable picking list is created via List › Print. The picking list cannot create reservations.

System steps

1. Run MB25 to review open reservations.
2. Run MBVR with a base date; choose "Set goods movement to allowed" and/or "Set deletion indicator".
3. Run MB26, adjust quantities, print the pick list, post.

Lesson 3 · Checking Availability and Missing Parts

Key concepts

Example of the static check: posting 321 for 20 pcs requires 20 pcs in quality inspection stock at that plant and storage location. Example of the dynamic check: 100 pcs in stock, 30 reserved for tomorrow and 20 for the day after – only 50 are available today, so a withdrawal of 60 triggers a warning or error. The dynamic check is used in IM (reservation, GI), SD (sales order), PP (production order) and Purchasing (stock transport order).

Prerequisites for the dynamic check

1. A checking rule assigned to the transaction (e.g. Create Reservation).
2. A checking group in the material master (MRP 3 view).
3. Scope of check defined for checking group + checking rule: include safety stock, stock in transfer, QI stock, blocked stock; receipts (PReqs, POs, production orders) and issues (sales requirements, reservations); with or without replenishment lead time (RLT).
4. Message type (E/W/I) per movement type for availability/non-availability.

Replenishment lead time: normally requirements beyond the RLT are considered available because they could be procured in time. With Without Replenishment Lead Time set, the system ignores RLT and checks strictly. Example from the handbook: stock 100, reservation of 80 in 2 days, PO receipt of 50 in 4 days – a new requirement of 30 in 1 or 3 days is not available; on day 5 30 are available but not 80; after the RLT everything is available.

Missing parts check

A missing part is a requirement that could not be covered when it was due; when goods arrive they should bypass the warehouse and go straight to the point of use. The missing parts check informs the GR clerk (message at GR) and the MRP controller (mail) automatically. It reuses the dynamic availability check elements (checking group, checking rule, scope). Settings (OMBC):

• Activate per plant; choose summarized (one list per MRP controller, material document and plant, no MRP elements) or non-summarized (one mail per material with up to five MRP elements).
• Checking rule and scope with a checking horizon (days into the future, today counts as day 1; without horizon only past uncovered requirements count).
• Checking rule assignment at transaction level; a movement-type-level rule takes precedence, but only works if a transaction-level entry exists.
• Mail recipient: the MRP controller's user ID; otherwise the plant's central missing part expediter. (Not the same field as the general recipient for MRP controller mails.)

Configuration (IMG)

Unit summary & exam focus

T-codes in this unit

Self-check questions

1. How can reservations arise automatically?
   Answer

   As dependent reservations for orders, networks and WBS elements, and as stock transfer reservations from storage-location reorder point planning in MRP.
2. Which header entries cannot be changed after a reservation is saved?
   Answer

   Movement type and account assignment.
3. Why might a reservation item not be found when searching in MIGO?
   Answer

   Its Movement Allowed indicator is not set.
4. What two roles does the base date play in MBVR?
   Answer

   It selects reservations with header base date ≤ the date, and it is the start for calculating the key dates for setting Movement Allowed (+ workdays) and deletion (– days).
5. What is the difference between the static and dynamic availability check?
   Answer

   Static checks current physical stock types to prevent negative stock (no settings); dynamic checks available quantity including planned receipts/issues according to a configured scope.
6. Who receives the missing parts message if the MRP controller has no user ID?
   Answer

   The central missing part expediter defined for the plant.