result & Conclusion We believe that this study is an important reference model and addition for Palestinian companies that can help them calculate the effort needed to perform their software projects in terms of cost, delivery time and number of resources.We would like to add that we have designed the extension of the Triangulation method to be able to control and adjust the project delivery time by varying the allocated resources (e.g.,the number of engineers).This model can be used as a guideline to get better and more accurate effort estimates.