Two advantages :

1. It increases the function traceability.
2. It helps to improve the serialization of processes.
3. It is able to identify/locate different tests involved in processes.

OR

• Track a requirement from conception through to delivery,

• Plan and manage testing and defect triages better,

• Reduce leakage, wastage of precious resource on non-priority, or simply nonrequirements,

• Document adequately, and

• Work effectively in a world of integrations.

Two disadvantages :

1. This needs advance planning.
2. It becomes time consuming in many of the cases where requirements are more.
3. Incomplete work results into: