The Contingency Plan
If significant problems do occur and they are unable to be resolved within a reasonable time period (again this will depend on the scale of the implementation), then pre-prepared contingency plans must be put into action. These may involve restoring old systems (and so 'gaps' in live data may need to be taken into account) or foregoing functionality in the new system where problems are occurring. At the point of invoking contingency plans, it must be agreed over how long a period of time these are to operate - during which time attempts to rectify problems with the new system can be made. Contingency measures should be just that - last resorts made in order to maintain core business functions - but depending on the nature of the business function/s affected it may be that the next 'window of opportunity' for reinstating the new product is independent of the time taken to resolve the problem, e.g. you might wait to begin a new annual processing cycle.
