Explain why waterfall model is more advantageous than adhoc methods.     

Ad-hoc Process Models-"Process capability is unpredictable due to the software process is constantly changed or changed as the work progresses. Schedules, budgets, functionality, and product quality are usually inconsistent. Performance depends on the capabilities of individuals and changes with their innate skills, knowledge, and motivations. There are few stable software processes in evidence, and performance can be predicted only by individual rather than organizational capability."

So to overcome this problem waterfall model gives the following advantages:

a. Waterfall model is easy to follow, however real projects rarely follows this approach.

b. Iteration is not needed.