Research On The Risk Cascading Propagation Of Project Portfolio Network Based On Structural Complexity

In the environment of fierce market competition and diversified customer demands,facing the increasing reduction of R&D cycle,complicated technical requirements and scarcity of enterprise resources,project portfolios have become more and more prevalent in enterprises.Although enterprises try to maximize project benefits,achieve strategies and enhance competitiveness through multi-project complementary advantages,the success of project portfolio is still low.How to manage project portfolio risks effectively has become a key issue to ensure enterprise sustainable development and maintain competitive advantage.However,project portfolio risk cadcading propagation is a great challenge to project portfolio risk management.This risk propagation mainly results from structural complexity of project portfilio constructed with structural dynamics and relationship diversity(interdependence).The structural complexity makes the project portfolio no longer accumulations of single projects,but a complex network with a dynamic Interactive effect of multiple elements and relationships.Moreover,project portfolio risk is no longer isolated,but highly related due to this complexity.Some project failures could cause the risk cascading propagation problem,which affect the normal implementation of portfolios.Consequently,it will lead to severe losses,and might even cause enterprise bankruptcy.In view of this,how to reduce harms caused by risk cascading propagation,improve the resisting ability of project portfolio network,and ensure the successful implementations of projct portfolio has become an important problem,which affect the sustainable and healthy development of enterprises.However,literatures on risk cascading propagation at a portfolio level caused by structural complexity are relatively sparse.Moreover,researches on project portfolio complexity maily forcus on the source and classification of complexity.There is no study deeply analyzed the impact mechanism of complexity on project portfolio risk cascading propagation.In addition,although reseaches of risk propagation are various,there are relatively few studies on risk cascading propagation in project portfolio network.Methods of risk propagation are not applicable.Therefore,it is significance both in theory and practice to study project portfolio network risk cascading propagation based on structure complexity.The main research work and conclusions are shown as bellows.(1)The generation and evolution rules of project portfolio network considering influences of structural complexity are put forward.Factors affecting the generation and evolution of project portfolio network are discussed.By analyzing the impact of structure complexity on the project portfolio network,it is pointed out that structural dynamic is the fundamental reason of project portfolio network generating and evoluting,and structural relationship diversity affects the topology of project portfolio network.To develop the generation rule of project portfolio network,the generating process is regarded as the project selection process of maximizing the benefits of portfolio,satisfying cost and risk constraints,and joining or exiting portfolio according to interdependences and strategies.Considering the evolution of project portfolio network as a process of the network stability and network adjusting with changing of project statuses,the evolution rules are constructed.Finally,a case study is carried out to verify the rationality and validity of these rules.Compared with traditional project selection models,the projct portfolio network can provide a better portfolio structure for enterprise decision makers,which can make them better use of resources,increase benefit and reduce project failures.Moreover,these rules can help managers better understand the internal structure of project portfolio and grasp the changes during multi-cycle.Subsequently,it can give some supports for project portfolio management.(2)The risk cascading propagation model of project portfolio network based on structural complexity is constructed.By analyzing the influence of structural complexity on risk cascading propagation,it is pointed out that structural dynamic affects the risk propagation process of project portfolio network in different cycles,and the structural relationship diversity impacts the risk propagation degree in the same cycle.Based on cascade failure theory,the risk cascading propagation model of project portfolio network is proposed.In this model,it analyzes the risk propagation stages and triggering mechanism.Through numerical simulation,this paper discusses the impact of network topology factors on risk cascading propagation,such as different project risk capacity distribution,different type of node project,and different node project interdependence.The results show that,in order to improve the resisting ability of project portfolio network on risk cascadding propagation,the limited resources of portfolios should be allocated reasonably to protecte these large degrees and interdependences projects,which is core projects with more related to other projects.Meanwhile,the differences of project risk resisting capacity should be reduced as much as possible and strenth protections for projects with poor risk resisting capacity.(3)A risk cascading propagation model of project portfolio network under attack-failure structural state is given.Considering reasons of project failure,this paper explores the risk cascading propagation problem under enterprise competitors attackting.Grey attack information is introduced to characterize the accuracy of project portfolio network topology information obtained by enterprise competitors.The grey attack information measurement models of node project degrees and interdependences are constructed.Subsequently the risk cascading propagation model of project portfolio network based on grey attack information is proposed.The impacts of grey node project degree attack information,node project interdependence attack information and project risk capacity under grey attack information on risk cascading propagation are analyzed by simulations.It is found that,in order to improve the enterprise's resising ability to the project portfolio network risk cascading propagation caused by competitors attacking,it is necessary to reduce project portfolio information spillover,and avoid core project failures.(4)Based on cascade failure control theory,the risk cascading propagation control model of project portfolio network under failure-repair structural state is established.Considering the risk cascading propagation control problem when enterprises take rescue measures to repair projects,a risk cascading propagation control model based on failure node repair strategies is proposed.The model is described from two aspects: failure node repair strategy and failure node repair mechanism.Then the effects of different failure node repair strategies,different node project failures and different node project repair ratios on risk cascading propagation of project portfolio networks are analyzed through simulations.The results show that,risk cascading propagation can be control through repairing high degree projects and increasing the repair ratio.In addition,the risk cascading propagation problem caused by failures of large node degree project should be considered because this kind of project failures could lead to a severer risk cascading propagation.