SYSTEM ANALYSIS AND DESIGN
System development life cycle
Systems Development: is the entire process of creating an application, gathering user requirements, designing the database, designing the modules, coding the programs, testing the product and implementing it. The historical perspective provides insights that inform today’s work. The history started with business applications created in the 1950’s, develops under the influence of legacy systems, and evolves together with technological and social factors. The significance of system changes has increased. Moreover, many specialists now need certain skills in the analysis, understanding, and evaluation of the system ...view middle of the document...
Such processes were carefully designed using grid diagrams and flowcharts. There was great precision in the design of forms to record data, filing systems to manage paperwork, and the use of summary reports to act as control points in systems. For example, spreadsheets have been extensively used for many years prior to the introduction of Lotus 1-2-3 or MS Excel. There was also considerable attention given to human behavior during the business process the precursor to ergonomics.
Systems were initially implemented by paper and pencil using ledgers, journals, indexes, and spreadsheets. They have always had some interesting filing systems, everything from cards and folders, to storage cabinets. Perhaps the earliest mechanical device was the ancient abacus used for simple math which is still used even to this day. The late 1800's saw the advent of cash registers and adding machines as popularized by companies like NCR in Dayton, Ohio under John Patterson who also introduced sweeping changes in terms of dress and business conduct. This was adopted by Thomas Watson, Sr. who worked for many years at NCR and carried forward these practices to IBM and the rest of the corporate world. Also, Burroughs was a major player in the early adding machine industry. The first typewriters were also introduced in the late 1800's which had a tremendous effect on correspondence and order processing. This was led primarily by Remington Arms later to become Remington Rand.
In the early 1900's, tabulating equipment was introduced to support such things as census counting. This was then widely adopted by corporate America. Earlier you were to run into old-timers which were describing how they could program such machines using plug boards. Punch card sorters were added as an adjunct to tabulating equipment.
During World War II, both the U.S. military and industrial complex relied heavily on manually implemented systems. They did it so as well that many people, including the Japanese, contend it gave the Allies a competitive edge during the war.
Manually implemented systems have been with us long before the computer and are still with us today. The first on-line, real-time, interactive, database system was double-entry bookkeeping which was developed by the merchants of Venice in 1200 A.D. The UNIVversal Automatic Computer was developed for the military at the end of World War II. More importantly, the UNIVAC I UNIVversal Automatic Computer was introduced in 1951 by J. Presper Eckert and John Mauchly. The 1950's represented the age of experimentation for corporate system and the emphasis was not on implementing major systems through the computer, but rather to develop an assortment of programs to test the machine as a viable product.
System Development in the 1960s
In the early days of the Data Processing profession there was no system development engineering discipline. For these early systems, the requirements were gathered haphazardly using no particular...