It is a series of guide posts to keep one going in the right direction.

• It is a series of guide posts to keep one going in the right direction.

• It reduces wastage of time and cost.

• It encourages co-ordination and effective organization.

• It is a tentative plan which undergoes modifications.

• It has to be geared to the availability of data and the cooperation of the informants.

• It has also to be kept within the manageable limits.