Research On Divisible Project Portfolio Selection Problem With The Consideration Of Risk Factors

Along with the rapid development of market economy,the corporations realize diversified and expansive investment.This makes the project portfolio increase as well.In order to maximize the profit of investment,how to select project portfolio is becoming one of the most urgent problems for the corporations.The problem that how to select an appropriate portfolio to meet a corporation`s objectives within the indispensable constraints is defined as the project portfolio selection problem(PPSP).According to whether divisibility of the project is considered when choosing the optimal project portfolio,the project portfolio selection problems can be divided into two major classes: project portfolio selection without divisibility and project portfolio selection with divisibility.In this paper,we do the research under the premise of project divisibility.According to the existing research on project portfolio selection,this paper finds that: in certain circumstances,initiative interruptions can increase the benefit of the project portfolio and promote the corporations` long-term development,but the existing research on project portfolio selection with divisibility ignored the unavoidable risk factors.It is worthy to point out that the risk factors always played an important role in the project selection,and the risk factors determine the success or failure of the project portfolio selection.As a consequence,it has a profound theoretical and practical value to study the risk factors in divisible project portfolio selection problem.Therefore,the major research of the paper is to put forward the definition of the divisible project portfolio selection risk,and to build the divisible project portfolio selection model considering risk factors.For the shortage of the existing research on divisible project portfolio selection model,this paper first uses lack rate of profit to define the risk of divisible project portfolio selection,then gives out its mathematical expression,at the same time,the step by step solving process of the mathematical expression is proposed.After that,risk is introduced to the original model of divisible project portfolio selection,and the divisible project selection model with risk factors is constructed for the first time.Next,this paper quantifies the enterprise risk attitude.Meanwhile,the specialized mathematical expression and value ranges of enterprise risk index are given out.Then the enterprise risk attitude is applied to the model built above,so the divisible project selection model considering profit lack rate and enterprise risk attitude is created.In order to reflect the practical situation,a simplified model is proposed by simplifying the risk factors.In the end,to verify the essence of studying the risk factors in divisible project portfolio selection problem,as well as the feasibility and advantages of the simplified model,this paper takes a set of simulation data for example.Through GAMS software,we can get the optimal solutions of the new divisible project portfolio selection model with risk and the existing project portfolio selection model.Then the paper makes a comparison between the two optimal solutions.Besides,in order to verify the necessity of introducing enterprise risk attitude to the model,this paper also makes a research on the optimal project portfolios when the enterprise takes different risk attitudes.After analyzing and comparing the selection results,the paper gets the following conclusions: the simplified model built in this paper has an obvious advantage over the old divisible project portfolio selection model whether the enterprise risk attitude is considered or not;under the same enterprise risk attitude,the simplified model`s optimal solution is much better than the old model`s when other constraints are the same;when the lack rate of the profit presents the divisible project portfolio selection risk,the corporation can get a better benefit when taking negative risk attitude,but it does not mean that the more negative the risk attitude is the better the result is,but concrete analysis should be made according to concrete circumstance.