INT- CALCy

Int-Calc
Intelligent Calculation System


Int-Calc

Complex calculations have as many twists and turns as the real world. Deciding when to use a particular calculation can reduce the search space dramatically, saving time and effort. Int-Calc does just this by integrating the decision process into the calculation process when necessary.

Expert knowledge about the appropriateness of the calculation can be introduced at many stages giving full knowledge base access and ensuring best practise.


The NHS Pensions Agency is an agency of the Department of Health with responsibility for handling all of the National Health Service pension requirements. To help in this, they have a suite of six major Knowledge Based Systems (KBS) and several smaller systems which are used by up to 350 networked staff every day.

This makes them one of the largest KBS and perhaps the longest lived of any expert system. Since their inception in 1989, Charms and related systems have handled over 10 million benefit award, estimate and associated calculations.

The systems handle the Agency's pension awards, transfers and added benefit purchase calculations for the members of the NHS Pension Scheme (with a few exceptions). They provide estimates and process early retirements, redundancies and transfers into and out of the scheme. There have been changes to the legislation since its inception in 1948, with very little superceded and almost all added to existing legislation. This emphasises the complexity and importance of cut off dates and temporal relation decisions necessary in the calculations.