A risk based economical approach for evaluating software project portfolios
Portfolio management of software development projects using COCOMO II
The software project portfolios mentioned in these two papers are quite different from the software portfolio I am working and doing research on. The software portfolio they talked about are the portfolio used to evaluation investments on software projects to maximum the profits and help manager to optimize resource distribution, while our software portfolio is used to monitor the health state of software projects and help users to improve their development practices. However, there is an opportunity that these two kind of portfolio can cooperate together.
When estimate a project,  use a term called Risk Level and  introduce a set of factors to represent the similar attribute. In our portfolio, the chance a project may fail is indicated by the health state of the project. It is more accurate and objective than the risk value given by the manager. If we combine these two kind of portfolio and use our portfolio to evaluate projects' risk level, the estimation of final profits should be more reasonable and accurate.