ABC – Criticisms

i was going through the ABC chapter in the bpp text, and came across the following criticisms which i couldnt understand, please explain them properly sir :

1. Cost apportionment may still be required at the cost pooling stage for shared items of cost such as rent, rates and building depreciation. Apportionment can be an arbitrary way of sharing costs.

2. A single cost driver may not explain the cost behaviour of all items in a cost pool. An activity may have two or more cost drivers.

3. Unless costs are ‘driven’ by an activity that is measurable in quantitative terms, cost drivers cannot be used. What drives the cost of the annual external audit, for example?

4. There must be a reason for using a system of ABC. ABC must provide meaningful product costs or extra information that management will use. If management is not going to use ABC information for any practical purpose, a traditional absorption costing system would be simpler to operate and just as good.

5. The cost of implementing and maintaining an ABC system can exceed the benefits of ‘improved accuracy’ in product costs.

6. Implementing ABC is often problematic, due to problems with understanding activities and their costs.

7. ABC is an absorption costing system. Absorption costing has only limited value for management accounting purposes.