This may also help in addition to above answers :
1. Ask for bifurcation of duties of various persons at various departments to how many persons are needed to employ.
2. Logically decide how many persons are required pere machine if labors are employed.
3. Ask the above question to Engineer (he is generally not aware of accounting jugglery)
4. Specially check those employees records whose attendance is full (with no leaves).
5. Approach the HRD officer and Recruitment Officer when the employees were last appointed. Ask verbally first and then check it with records.
6. Other points are to be taken on the basis of practical application of Auditing Principles.