Why is it important for the various modules in a hierarchal planning system to achieve consistency? Why is such consistency not always maintained in practice?

Why is it important for the various modules in a hierarchal planning system to achieve consistency? Why is such consistency not always maintained in practice?

It is not important for the various modules in a hierarchal planning system to achieve consistency because consistency is rarely ever maintained in practice.

Inconsistencies can lead to effective modules and confidence in the plans. While obviously important, however, consistency may not be achieved in practice because different groups are often responsible for different parts of the plan. Consistency between modeling assumptions and data must be enforced institutionally.

Inconsistencies can lead to ineffective modules and a lack of confidence in the plans. For instance, if unreasonable capacity numbers are used in the aggregate planning module, the resulting plans will be far from the actual execution sequence. The result will be that the aggregate plan will offer little help in identifying bottlenecks, specifying staffing needs, etc. While obviously important, however, consistency may not be achieved in practice because different groups are often responsible for different parts of the plan. Consistency between modeling assumptions and data must be enforced institutionally.

Inconsistencies can lead to ineffective modules and a lack of confidence in the plans. For instance, if reasonable capacity numbers are used in the aggregate planning module, the resulting plans will be far from the actual execution sequence.