PP (Production Planning) Interview Questions

FAQ on SAP PP (Production Planning)

Q1: How to configure the planning calendar for the ATP calculation where goods are shipped every other working day?

Ans: Use Transaction MD25 and define calculation rule for every other working day. Check the lot size settings in OMI4 and maintain relevant data in MMR.

Q2: We have two different production lines with different operations. One production line works 5 days a week and the other 7 days a week. The factory calendar is assigned to the plant for 5 days a week. This calendar is checked when MRP is run. How can we assign 5 day a week and 7 days a week against a factory calendar to the related resources? Is it possible to have two types of calendars?

Ans: Assign factory calendars to the work centers.

Q3: What is the difference between by-product and co-product and how do you differentiate them in a BOM?

Ans: In case, of Co-product costs are settled with an apportionment structure. In case, of By-product the price of this by-product is credited to the order or the material stock account of the lead material being manufactured. Co-Product as well as by-product are defined as BOM Components/Items. Both of them have negative quantities. ( Not all negative quantity items fall under these categories!). When BOM is created for FERT, you can see one indicator in COMPONENT DETAILS screen for co-product. You need to define the co-products with this special indicator.

Q4: What are some important tables used in PP (Production Planning)?

Ans: For orders:

CUAFVD dialog structure for order headers and items
AFPO - Order item
AFFLD Order: Dialog table for order sequences (AFFL)
MOPER Operation for production order
KBED Capacity requirements
AFRU Order completion confirmations
RESB Reservation/Dependent Requirements
AFFHD Structure of PRT's in orders
SOPER Sub-operations
SAFRU Sub-operation confirmations
SKBED Capacity requirements for sub-operation
MRP table is MDTB.

For PI:

CAUFV - AFVC Operation within an order
AFFT Order Process Instructions
AFFV Order process instruction values

Some other tables of interest:

PLKO, MAPL, PLAS.

Bills Of Material

Q5: We have a BOM - 'A' with two packing materials 'X' and 'Y'. For 1000 units of 'A', 1 packing material of 'X' is required and for 50 units of 'A', 1 packing material of 'Y' is required. Base quantity of 'A' is defined as 1000. How can I define 'X' & 'Y' or in fact 'A'?

Ans: Make the base quantity of 'A' as 5000. The resulting component quantities would be 5 of 'X' and 100 of 'Y'.

Work Centers

Q6: Can we have more than 6 standard values in standard value key?

Ans: One way to achieve this is to create another operation step using the same work center. However this shall be with a control key that is not a milestone. When the milestone operation is confirmed, the previous operations up to the next milestone are automatically confirmed. To get the desired number of standard values , all the 'non milestone' steps can be built depending on the need.

Routing

Q7: Can we use same routing for materials undergoing the same process/operations? Can we avoid separate routing for each and every material produced?

Ans: Presume that there are 50 products and the fabrication shop uses a set of 10 machines. If all these products use the same settings of the machines, Reference Operation Sets (task list type S) can be setup for common processes that use the same work centers. However costing, scheduling and capacity will be affected if each product has different setup time and Reference Operation sets can not be used.

A routing for each material number ( type N or R) has to be set up and within that routing, the Reference Operation Set can be used.However, you can by try utilizing the KMAT material and product variants invariant configuration to avoid separate routing for each material.

You may create a routing group. Go into routing creation and enter the plant and the group name. If you want you may name the group, else name is assigned by internal counter). Create the routing with the work centers, operation times, etc. Go to the "Header overview" screen and click on the "Mat Alloc" screen. Fill in the blanks with all the material masters that use this routing.

Q8: Scheduling times can be defined in the material master record by;

# entering the in-house production time. This value can be updated from the routing by the system.
# entering the setup, tear down, processing, and interoperation times. If these values are maintained, the system determines the in-house production time on the basis of lot size.

How do you get the system to update this value from the routing?

Ans: In routing, carry out scheduling. Go into the routing operation overview and follow Extras -> Scheduling -> Results. The pop-up window displays the scheduling data. At the bottom there is a pushbutton to copy the scheduling data to the material master Check this push button to update master data.

Q9: We have deleted a group key in an operation in routing and the same does not appear for this routing (CA02). But we noticed that entries are maintained in table PLPO and the deletion indicator is not set. How does the system remember this deletion of group key?

Ans: You may look at the tables PLKO, MAPL and PLAS.

Sales & Operations Planning

Q10: We defined SOP in months. However, during SOP transfer to demand management, our independent requirements are appearing in weeks. How can we correct this from weeks into months ?

Ans: Check transaction OMPA for general split. OMPS - based on the MRP group. Ensure that MRP group assigned to the material. Delete any allocations in these tables.
Then periods will be transferred to Demand Management with the same splits as in SOP. Also, check whether the value of period is set as "month" at your plant level in Transaction 'OMP7'

Demand Management

Q11: Sales quantities in SOP for certain days are transferred into Demand Management and are shown as planned independent requirements. We need to keep the settings in SOP and change the periods in Demand Management? We would like to have a rolling horizon, for ex: the following 4 weeks on a daily basis, after that on a monthly basis. What is the best way to do this?

Ans: Use the automatic period split function.

M R P

Q12: We have a lot of size procedure here which is creating more order proposals. How do you set the limit value for the maximum number of MRP order proposals per date in IMG?

Ans: Under customization, try materials management->consumption based planning->maintain all plants

Q13: What is the difference between "planned consumption" and "Unplanned consumption"? Can safety stock calculation be done on either of these?

Ans: While customizing movement types (OMJJ) it is defined as to which set of consumption values gets posted during the material movement. For some, it may always be the total consumption and for some, it is always the unplanned one and for some, it is dependent on whether the issues were done with reference to a reservation ie., a planned consumption.

The way these consumption values are taken into account in MRP is defined in the customizing of MRP types.

For Reorder point planning (VM) the total consumption is used to calculate the safety stock and the reorder point.
For Forecast-based planning (VV) the total consumption is used to build the forecast which will be used to compile the order proposals.
For Deterministic MRP (PD) the unplanned consumption is used to calculate the forecast which in turn is added to the actual demand.

Q14: We want the system to run a single level MRP automatically on receipt of sales order. How to configure triggering event based MRP?

Ans: This can only be run if the material master has planning strategy 41 (made-to-order) in the MRP2 view. We need to run for other MRP types. We have to create a user exit in the sales order processing (VA01) to start MRP based on data from our sales transaction.

Q15: We have an assembly 'A' using a subassembly 'B'. 'B' in turn uses raw material 'C'. Item 'A' is an MPS and is duly marked in Material Master. Item 'B' and 'C' are marked as 'PD'. When demand for 'A' is entered and MPS is run , upto which level the requirements are taken care of?

Ans: MRP can be run depending on your requirement. For example:

Single Item / Single Level from MPS - Transaction Code MD42 - Only the top MPS item ( 'A' in this case) is planned and dependent requirements will be passed to MRP item ( 'B' ) . Run MRP, Transaction MD02 on 'B' to plan it and all MRP items below.

Single Item / Multi Level from MPS - Transaction Code MD41 - All levels are planned - A, B & C

Total Planning from MPS online or background - Transaction Code MD40 or MDBS

Without marking the checkbox " Process MRP materials" is like case ( 1) above and with the checkbox marked is like case (2 ).

Production Orders

Q16: We get an error message "Control parameters for scheduling not defined" while creating test production Orders. Why?

Ans: Before you attempt creating Production orders, configure your
Order types- Transaction Code OPHJ
Order type Dependent parameters - Transaction Code OPL8
Backorder Scheduling - Transaction Code OMIH
Scheduling Levels - Transaction Code OMIF

Q17: We are trying to create Purchase Requisition from MRP run. We have material, info Record, Source list, Demand in place. MRP is always creating plan order. Why?

Ans: Check the procurement type in MRP view of material master. Check 'Create Purchase requisition' indicator while running MRP. If you want purchase requisitions to be created in the opening period, select the for MRP control parameter 'create purchase requisitions' as '1'.

Q18: what is the option "Documented goods movements" on Selection of Individual Object Lists (transaction code CO28)?

Ans: Use Transaction code OPL8 to customize by choosing the order type, select all the checkbox under "Documentation of goods movements" at the bottom of the page. Create a new Production order, make GI to it, and run the report.

Q19: We would like to have a report/inquiry that would indicate variances (materials, material quantities) between material recipe and actual process orders. We tried ME2M but this gives us a list of purchasing documents and not the consumption deviation. Where can I get such consumption deviation (master recipe Vs. Process> Orders)?

Ans: Do a data collection first.

Menu Path - Accounting->Controlling->Product cost acctg->Process mfg->Information system->Cost object hierarchy->data collection

(If you are using order hierarchy you would select order hierarchy in place of cost object hierarchy in the menu path.)

Then, Accounting->Controlling->Product Cost Accounting->Order Related Production->Information System Choose Report Period Costing - Target/Actual production variance

Q20: We have two components ( 'X' & 'Y' ) in a production order in a process oriented production process. When 50 numbers of component 'X' are issued, we need the system to automatically issue 100 numbers of component 'Y' based on the ratio of 1 to 2. Where do I specify these ratios?

Ans: You can define the ratio in BOM and material may be issued with reference to BOM.

Q21: We have two storage locations are '0001' and '0600'. Default storage location in Process order is always '0001' What determines this default location?

Ans: Look into OSS notes: 100757, 63493, 96262, 87843, 82033, 64946. The Storage location as configured in the Supply area has the highest priority.

Q22: We need to do GI of components to production order using Back-flush. The component stock is managed in Batches. The Batch to be back-flushed

Ans: With the following settings, the batches are selected the moment the production order is released.

1: Set up batch determination the way that the batches in batch selection are sorted the right way. e.g. sorted by expiry date
2: Use automatic batch selection in disp view.
3: Ensure that the components are allowed to be back-flushed (material master/ work center) is selected by FIFO from the issue storage location. How can we set this up?

Q23: We want to report on several status combinations like each order that has status 'Not deleted' and 'Not technically completed'. What set up is required?

Ans: Check transaction CO28. In the selection screen note the possible selection 'System Status'. You can select TECO for technically complete an DLT for deleted from the list. Select the Excl. indicator also.

You may also try transaction CO26 (Logistics -> Production -> Production control -> Control -> Information systems -> Order Info System -> Object overview). Before executing the transaction report, combinations of statuses can be selected or exclude them.

Q24: How can we shut off the "automatic costing indicator" and the "automatic scheduling indicator" which go on when the production order is released?

Ans: For "no automatic costing" follow the IMG path
Production -> Production orders ->Master data -> Order - >Define order type dependent parameters
Select the order type for which u automatic costing is not required. In the controlling settings, select "no automatic costing"

For "no automatic scheduling", follow the IMG path:

Production ->Operations - >Scheduling -> Define control parameters

Select the order type and go to details. Deselect " automatic dates "

Alternatively, you can find indicators in the control key, which is in the routing. Transaction OPL8 gives you costing indicators (Order type dependent parameters), and OPJU (control table for scheduling) gives some scheduling options.

Variable Size

Q25: How can I use variable size items?

Ans: For example, consider an item A with 'kg' as base Unit Of Measurement(UOM) and 'm3' as stock keeping/issue unit. Conversion factor is 1kg = 2.4 m3.
In the BOM of 'B' ,number of A required are specified (say 5).

Specify the 3 variable dimensions i.e. length, width & thickness- say 2000mm X 3000mm X 4mm = 0.024 m3

As per BOM - 'B' , the quantity of A required is 0.024 X 5 = 0.120 m3

If a production Order is released for 15 numbers of 'B' , the quantity of variable size unit will be 1.20 m3.

You can change the length, width or thickness in the production order & check the resulting variable size item quantity. At the same time, this requirement can be seen in 'kg' in stock/requirement list.

Q26. Can MRP be carried out for one particular level of a bom ( Level code: 0001/0002 etc).

Ans: Yes it can be done by running for specific materials (Single Material Single Level)

Q27. How Requirements (PIR, Sales Order, Customer Requirement) are reduced after they are produced?

Ans: Reqmts are reduced automatically after Delivery is made to the Particular Order
(In case of Strategy 11, the PIRs are consumed after the GR for Production Order)

Q28. Can't one material be assigned to more than one operation in a routing?

Ans: One material from a BOM CANNOT be assigned to different Operations. It can be done by defining the material for so many times as required in the BOM

Q29. How to insert an inspection checkpoint at the end of an operation?

Ans: If in process sample is to be defined, assign inspection type 03 in the Material Master.Then create MICs and assign them in the Routings. System automatically generates the Inspection Lots

Q30. Where have we to specify the teardown time in one operation?

Ans: Teardown time can be defined as one of the Standard Parameters...

Q31. How is the process time calculated in a WC when both labour, Machine categories exist?

Ans: Scheduling is done based on the Capacity Category we define in the Workcenter

Q32. How to create object dependencies in a BOM FOR A CONFIGURABLE MATERIAL?

Ans: Go to Extras -> Object Dependency -> Assign

For this, you need to create Characteristics and Class (of Class Type 300) earlier

Q33. Can anybody explain to me why work scheduling view is required for semi-finished and finished products? (Because we'll mention all details in MRP views)

Ans: We need to maintain working scheduling view in order to make that finished or semi-finished goods available for production as we assign production scheduler and production scheduler profile in this view, if not maintained conversion of planned order to production will not be possible.