Planning and execution phase remains the most important phases. This is because in planning phase all the proper steps which are to be performed are laid out properly and in an orderly manner like allocating resources, setting deadlines, budget and cost estimation etc. The work or steps to be carried out in all the other phases is set right here in planning phase. After planning execution is most crucial. Things which are written on paper now should be bought into action which is done in execution phase. I feel closing phase is not that important as it includes most of the paper work for the completed product.