Work centers in SAP PP

What is a work center in SAP?

  • Can be a machine, tool, device, person or a group of these
  • Is a spatial area within the work system of an enterprise
  • Is an area where operations are executed
  • Used for defining persons and machines involved in operations
  • Used for modelling costs incurred by operations
  • Used for specifying available capacity and scheduling structures
  • A work center is plant-specific
  • A work center can be created using TC CR01
  • A work center can be maintained using TC CR02
  • A work center has various views: Basic data, default values, capacities, scheduling and costing

Work center views

Basic data view

  • Responsibilities and plan relations
  • Standard value keys for scheduling and capacity planning

Default values view 

  • Default values for routing

Capacities view

  • Formula for capacity requirements calculation
  • Capacity of work center

Scheduling

  • Formula for scheduling tasks

Costing

  • Cost centers for work center and activity types

Work center categories

The category of a work center can be maintained using TC OP40.

Work center categories enable control over work center usability in routings.

Some work center categories can be used in certain routing plan types only.

Examples of work center categories:

  • Machine
  • Machine group
  • Labor
  • Labor group
  • Plant maintenance
  • etc.

Work center task list usage

Task list usage allows for addition control over work center usability for different task types.

Task list usage could e.g. be set to:

  • “only routings”
  • “only rate routings”
  • etc.

Work center capacity

Capacity objects can be maintained in a work center’s capacity view.

A capacity defines a service provided by machines or persons for some time.

A work center can have various capacities.

E.g. the following capacities could be assigned to a work center:

  • Machine capacities
  • Spare capacities for rush orders
  • Personnel capacities
  • etc.

Maintaining work center capacities

Capacities are added to a work center in the form of a capacity category.

Capacity categories can be created via the following path:

Production>Basic data>Work center>Capacity planning>Define capacity category

When creating a work center one can assign capacity categories in the capacity view.

Capacity categories can also be added to an already existing work center, using the capacity view.

Work center capacity header

Work center capacity header is specified and maintained for combination of plant, work center and capacity header.

In the work center capacity header one can specify:

  • Capacity planner group 
  • Factory calendar ID
  • Base unit of measure (e.g. H)
  • Daily work start and finish time
  • Total length of daily breaks
  • Capacity utilization rate
  • No. of individual capacities (e.g. several work centers can be grouped into one capacity)

In the work center capacity header one can also specify relevance for finite scheduling, use for several operations, overload % and long-term planning.

Maintaining shift sequences

Maintenance of shifts, break plans and shift sequences possible in TC OP4A:

  • The break plan is specified as a table comprising start time, end time and length of break
  • Shifts are specified as a table with start time, finish time and breaks
  • Shift sequences can be defined by assigning shift names to week days

Shifts, break plan and shift sequence can be assigned to a grouping.

The grouping can be assigned to the work center capacity header.

Pooled capacities

Pooled capacities can be used for modeling capacities used by various work centers.

Pooled capacities are created using TC CR11. In TC CR11, check the “pooled capacity” box.

Afterwards, pool capacity must be assigned to work center in the capacity view of the work center.

Pooled capacities can be displayed from the capacity view of a work center. But, pooled capacities cannot be maintained directly from the capacity view of the work center.

Formulas for capacity requirement and scheduling

Operation time length and capacity requirement are calculated using formulas.

Formulas can be customized using TC OP21.

Formulas for capacity requirement and operation time use standard parameters and values.

In order for formulas to use the correct parameters and values, parameters and standard value keys need to be created.

Standard value keys allow you to specify the parameters to be used in formulas of a work center.

Parameters are created using TC OPCX or TX OP7B.

Standard value keys are created using TC OPCM.

A standard value key specifies which parameters can be considered by a formula.

E.g., a standard value key could comprise the following parameters:

  • Setup time
  • Machine time
  • Labor time

The standard value key can then be mapped to the work center by entering the key into the general data section of the work center.

The formulas can also consider additional parameters, taken from the orders running on the work center (base quantity, operation quantity, number of operation splits).

When creating a formula in TC OP21 one can specify whether:

  • The formula can be used for scheduling 
  • The formula can be used for deriving capacity requirements

In SAP there are standard formulas for calculation capacity requirement (SAP006) and processing time (SAP002):

Capacity requirement = Standard value * Order quantity / Base quantity

Duration = Standard value * Order quantity / Base quantity / Number of splits

Scheduling basis

Scheduling basis is defined in the scheduling view of a work center.

In the scheduling basis one must specify the capacity category to be used as basis for scheduling.

A work center can have multiple capacities and the capacities can have different working times.

Therefore it is important to specify which capacity is to be used as scheduling basis.

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