Audit risk and audit strategies

Audit procedures may be classified into several categories, including:

1.Procedures designed to obtain an understanding

2.Tests of controls

3.Analytical procedures

4.Substantive testing of transactions

5.Substantive testing of balances.

Required

(a)Describe the relationship between the above five categories and how these need to be considered when designing audit strategies.

(b)How would consideration of the audit risk model affect the audit strategy and therefore the extent to which these types of procedures are performed?