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CHAPTER 11  ANALYSIS CONCEPTS AND PRINCIPLES                       277

                                While reviewing the request in the days before the meeting, each FAST attendee
                              is asked to make a list of objects that are part of the environment that surrounds the
                              system, other objects that are to be produced by the system, and objects that are used
                Before the FAST  by the system to perform its functions. In addition, each attendee is asked to make
                meeting, make a list
                of objects, services,  another list of services (processes or functions) that manipulate or interact with the
                constraints, and  objects. Finally, lists of constraints (e.g., cost, size, business rules) and performance
                performance criteria.  criteria (e.g., speed, accuracy) are also developed. The attendees are informed that
                              the lists are not expected to be exhaustive but are expected to reflect each person’s
                              perception of the system.
                                             3
                                As an example, assume that a FAST team working for a consumer products com-
                              pany has been provided with the following product description:
                              Our research indicates that the market for home security systems is growing at a rate of 40
                              percent per year. We would like to enter this market by building a microprocessor-based
                              home security system that would protect against and/or recognize a variety of undesirable
                              "situations" such as illegal entry, fire, flooding, and others. The product, tentatively called
                              SafeHome, will use appropriate sensors to detect each situation, can be programmed by the
                              homeowner, and will automatically telephone a monitoring agency when a situation is
                              detected.

                                In reality, considerably more information would be provided at this stage. But even
                              with additional information, ambiguity would be present, omissions would likely exist,
                              and errors might occur. For now, the preceding "product description" will suffice.
                                The FAST team is composed of representatives from marketing, software and hard-
                              ware engineering, and manufacturing. An outside facilitator is to be used.
                                Each person on the FAST team develops the lists described previously. Objects
                              described for SafeHome might include smoke detectors, window and door sensors,
                              motion detectors, an alarm, an event (a sensor has been activated), a control panel,
                Objects are
                manipulated by  a display, telephone numbers, a telephone call, and so on. The list of services might
                services and must  include setting the alarm, monitoring the sensors, dialing the phone, programming
                “live” within the  the control panel, reading the display (note that services act on objects). In a similar
                constraints and  fashion, each FAST attendee will develop lists of constraints (e.g., the system must
                performance defined
                by the FAST team.  have a manufactured cost of less than $80, must be user-friendly, must interface
                              directly to a standard phone line) and performance criteria (e.g., a sensor event should
                              be recognized within one second, an event priority scheme should be implemented).
                                As the FAST meeting begins, the first topic of discussion is the need and justifica-
                              tion for the new product—everyone should agree that the product is justified. Once
                              agreement has been established, each participant presents his or her lists for dis-
                              cussion. The lists can be pinned to the walls of the room using large sheets of paper,
                              stuck to the walls using adhesive backed sheets, or written on a wall board. Alter-
                              natively, the lists may have been posted on an electronic bulletin board or posed in


                              3  This example (with extensions and variations) will be used to illustrate important software engi-
                                neering methods in many of the chapters that follow. As an exercise, it would be worthwhile to
                                conduct your own FAST meeting and develop a set of lists for it.
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