Q$\mathrm{.}5$ Project Managers X$,$ Y$,$ Z of the various different companies but part of the Same Organization was attending an offshore Project Management summit. During that Summit each one of them were presenting Case studies which they are currently use and the success stories

Q$.$A $.$Z$-$Project manager$$s case study is more about a project method wherein project$$s overall architecture was ready along with new cost drivers, counting rules, equation and it uses Unadjusted Function Points. The project model is derived from the main project model which uses basic regression formula on historical project data and its characteristics

Please identify what project model would have been used and explain in detail? what are the various critical handling situation wherein this project model would have helped Z$-$Project manager to have a successful Project.