Firstly, putting a precise value
on many of the items is very difficult. Secondly, the chances are that the highest NPV items are also the most expensive and risky to do (so a few may use up all your funds).
Strategic Alignment Prioritisation
As an alternative approach, why not try my favourite
model for prioritisation, where each item is assessed for (a) value & (b) ease and placed on a 2x2 matrix.
Value, in this context, is derived from the strategic
objectives of the organisation; This will normally include profitability (as most have this objective), but also softer measures like employee satisfaction.
Ease is similarly based on a group of different measures, which includes cost but also takes into account the inherent
difficulty and risk of failure. Prioritised items will fall into one of four quadrants:
High Value, High Ease. Many of these items should be
in scope for your portal project.
As you are likely to succeed in implementing these and be able to demonstrate immediate benefits, they help to build confidence in the platform, the project and you personally.
High Value, Low Ease. Most of the really substantial
items will appear in this box. As the old saying goes, 'nothing worthwhile was ever won easily'. Your project should include at least one or two of these (for substance) but too many will use up all your funds and eat into your contingency, when things go wrong (so don't overdo it).