To support an effective PO, any tool or set of tools, whether off-the-shelf or homegrown, must satisfy a few fundamental requirements.
First, tools should adequately reflect the needs of three different types of users: portfolio managers, project managers, and resource managers. Second, they must integrate the different perspectives (finances, resources, and tasks) that make up the portfolio management function, so that when a change in one dimension occurs, it is reflected in the other dimensions as well. Third, they must deliver control information accurately and timely. And fourth, they must have an open architecture that allows the PO to customize them to its own, ever evolving needs.