Resource Items

Resources items represent the critical resources for which a long-term plan is necessary (for examples, a critical production center or work hours).

The Resource items are, as the Family items, auxiliary items used for the S&OP calculations. The Resource items are associated to the critical resources for which the aggregate workloads have to be planned for the future. Examples of such resources labour hours or machine hours. It is necessary to define, via the Resource item maintenance window, the number of decimal to be considered in the results display and in the records.

The Resource Item maintenance window displays a single panel which defines all the required parameters.

  Resource to be used by the solver. This cell defines if the resource is to be taken into account for the S&OP optimization procedure.  

 Integer values.  This cell indicates the S&OP optimization procedure has to associate integer values (instead of real values) to the resource. When this option is not selected, the optimization procedure can provide non-integer solutions, as 3,534 units for a labour resource item, which could be inconsistent in some case. When the integer option is selected, the algorithmic approach of the optimization procedure is different and much more complex and amounts to large computation times. It is the reason why it is advised to avoid selecting the integer option for a large number of resource items.

It is then required to fix if the Resource item is linked to the production activity or to the inventory management. For example, production resources as labour hours or machine hours are linked to the production activity, while inventory available cells in the warehouses are linked to the number of items kept in inventory.

When the check box External resource is selected, the resource is not considered as a constraint in the optimization procedure (as an example one can consider standard raw materials). Nevertheless, the resource consumption costs will be estimated.

When the check box External resource is not selected, the Capacity button is displayed. Via this button, the Resource Capacity Definition window is displayed.

The remaining cells define the costs associated to the resource, to be taken into account in the optimization process.

 Resource unit cost. This cell defines the hourly cost rate for production resources and unit inventory cost for inventory resources.

Resource minimum value. This cell defines the admissible lower bound for the resource level. For example, in many cases the number of workers (for some qualification) cannot be fixed to be below a certain level (in other words it is not possible to dismiss a large number of workers).

Resource maximum value. This cell defines the admissible upper bound for the resource level. For example, in practice it is not physically possible, in a given plant or production cell, to have more than a maximal number of people.

Required Resource Ending value. This cell defines the required resource level, expressed in units, at the end of the planning horizon.

Max. % of overcapacity. This cell defines to which extend the resource can be used above the nominal capacity.  For example, it can be admissible to recourse to overtime for at most 10% of the nominal capacity.

 Overcapacity unit cost. This cell defines the unit cost of overcapacity. This cost corresponds to an hourly rate for production resources and unit cost for inventory resources. Clearly, this cost has to be greater than the regular cost.

Max. % of capacity increase per period. Resource levels can be changed from one period to another. However, for numerous reasons, such periodic fluctuations are physically limited. This cell defines the upper bound for any periodic capacity increase.

 Capacity increase unit cost. Resource level changes induce specific costs. This cell defines the unit value of capacity increase.

Max. % of capacity decrease per period. Resource levels can be changed from one period to another. However, for numerous reasons, such periodic fluctuations are physically limited. This cell defines the upper bound for any periodic capacity decrease.

 Capacity decrease unit cost. Resource level changes induce specific costs. This cell defines the unit value of capacity decrease.

These parameters fix the setting for the S&OP optimization procedure.