The Fifteenth Level
Peter J. Denning · 1994
There is a connection between operating systems and workflow and groupware systems that is not widely appreciated. It has profound implications for the design and performance evaluation of computer systems. For over four decades the basic set of abstractions around which we structure operating systems has not changed. This is a testimony to the power and ruggedness of those abstractions, which have survived increases of processor speed and memory capacity exceeding six orders of magnitude, as well as an onslaught of parallel, distributed, and networked systems. This is about to change. The burgeoning workflow software industry did about $200 million business in the U.S. in 1993 and is expected to reach $2.5 billion in 1996. Workflow systems are based on a different conception of work than that on which the entire architecture of operating systems is based. The new conception of work is concerned with the fulfillment of commitments made between people, whereas operating systems treat work as the execution of computational tasks. (1) Since operating systems are the platform on which workflow systems rest, they will soon be forced to adapt to the new conception. This will compel the addition of a new abstraction, the business process, to the hierarchy of existing abstractions. It will also generate new meanings of performance evaluation and capacity planning. Concerns and Breakdowns Experienced by Organizations In the past decade, businesses that were not organized for consistent customer satisfaction have disappeared or met with wrenching hard times. The survivors have developed big concerns about how to reengineer themselves so that they can deliver products on time, offer services that consistently satisfy customers, maintain market credibility and reputation, and introduce new products and services faster than competitors. Many turned to information technology as a medium in which to