A number of factors are often taken into account in the organisation of any portfolio.  These may include:

political fairness – does the portfolio have ‘something for everyone’ – this may refer to business units, scorecard aspects or individual sponsors

value maximisation – is the business getting the greatest possible return for its investment?

resource optimisation – are the valuable (usually the most scarce) resources allocated to portfolio projects being kept busy?

risk diversification – can the organisation cope with the overall risk profile of the portfolio?