There is hope for executives imprisoned by their information systems. For years, an inability to change those systems quickly has thwarted promising business innovations. But several new approaches to systems development are now able to deliver business benefit fast. Not all of them are technically elegant. Not all of them will work in every situation. But, taken as a group, they make even major changes to information systems possible in weeks or months—rather than the years required by traditional efforts.

These new approaches achieve this, in part, by overturning many assumptions that underlie traditional development strategies, among them:

Old "legacy" systems must be totally replaced. In fact, legacy systems can often be supplemented or modified to provide most or all of the business value of a new system at a fraction of the time, risk, and cost.

Systems must be tailored to the unique way in which a company does business. Too often, customized systems development does not stand up to cost/benefit analysis. Especially for relatively standard processes that do not confer competitive advantage—general ledger, accounts payable, accounts receivable, and order processing, for example—the economics increasingly favor the purchase of...