Rapid Application Development

Rapid Application Development - RAD

The perceived slowness and inflexibility of the Waterfall SDLC menthod led to the development of a method that reacted quickly to change and adapted to changing conditions: a normal state of affairs in the fast-moving ICT industry. Where the Waterfall model would slowly chug forward, the market or technologies would change under its feet: sometimes by the time software was released, its was already out of date, irrelevant or incompatible with new industry standards.

RAD works differently. It develops products in a sequence of small upgrades: each release has slightly more functionality than the previous one, and over time the product matures into a finished product. In the time a team would take to fully develop a product using the SDLC, a RAD team might have released a dozen incremental versions.

The drawback of RAD is its short-sightedness: you could tell what would be happening in a week's time; you could guess what you'd be doing in a month; but trying to predict the state of a project in a year's time would be like reading tea leaves.

Unlike the SDLC, RAD makes it easy for customers to redefine their basic needs and expectations from a product.

A possible drawback of RAD, however, is that it would seem to encourage a "make it up as you go along" approach which will limit a product's scalability or future modification. The thorough planning and analysis of the SDLC would tend to create products that anticipated future needs and allowed expansion. A RAD product would more likely be hammered together to cater for immediate needs, but cope poorly if it had to be radically altered later.

I see SDLC like building a skyscraper, with the TV aerial on the penthouse fully designed before the foundations are even dug. I see RAD more like a shanty town that has new shacks thrown together as the need arises: quick, responsive, but not too elegant or enduring.

A classic example of rapid, successful development was the original IBM PC and its accompanying operating system - MS-DOS.

A classic example of development gone wrong is the game Duke Nukem Forever, which has been awaited for six years, with still no sign of release. It has won Wired News' "Vapourware Product of the Year" every year since 2001.