Working stress method is a method used for the reinforced concrete design where concrete is assumed as elastic steel and concrete act together elastically where the relation ship between loads and stresses is linear.

Advantages of wsm:-

1. It is a simple method.
2. Due to it simplicity it is still used for design for some complex structure such as over head water tank

Limitation of wsm

1. The assumption of linear elastic behavior and control of stresses within specially defined permissible stresses are unrealistic due to several reason viz, creep, shrinkage and other long term effect, stress concentration and other secondary effects.
2. Different type of load acting simultaneously have different degree of uncertainties.
3. The actual factor of safety is not known in this method of design