1. The impact on the business while changing, in both financial costs and time lost with the learning cycle;

2. The return on the investment, will the change offer enough higher productivity to justify the cost. If it doesn't then to change is an unnecessary cost. You don't NOT introduce change for change's sake since the money spent on a change that doesn't return a suitable return is a waste and may be just the difference between making a profit or going out of business.

To be worthwhile, a change MUST provide some real benefit other than glitter or the wow factor of saying you have the latest.