You client has stipulated that open-source software is to be used. Is this a functional or non-functional requirement? How early in the life-cycle model can this requirement be handled? Explain your answer.

In the beginning of the model

Explanation:

This is believed to be a non functional requirement because the non - functional type of requirement as platform restrictions, reliability and time of response. These requirements are meant to be handled during the beginning of the life cycle model because all planing and analysis should be centered around the fact that customers desires to adopt the open source model.