THE TRADITIONAL SYSTEM DEVELOPMENT LIFE CYCLE

6.3 THE TRADITIONAL SYSTEM DEVELOPMENT LIFE CYCLE

D e v e l o p m e n t is a v e r y d e l i b e r a t e a n d o r d e r l y a p p r o a c h to m a k i n g a s y s t e m a reality. A methodology is needed to provide structure to system development. There are many " t r a d i t i o n a l " s y s t e m d e v e l o p m e n t life cycles ( S D L C s ) f o r i n f o r m a t i o n systems, i n c l u d - ing DSS. E v e r y c o m p u t e r - a i d e d s o f t w a r e e n g i n e e r i n g ( C A S E ) t o o l h a s a d o p t e d a vari-

a t i o n . F u r t h e r c o m p l i c a t i n g m a t t e r s , e a c h o r g a n i z a t i o n t h a t d e v e l o p s a s y s t e m c a n cre-

a t e i n - h o u s e v a r i a t i o n s t o suit its s p e c i f i c n e e d s . E a c h m e t h o d o l o g y e m p h a s i z e s

d i f f e r e n t s t e p s i n d i f f e r e n t ways. B u t all S D L C s t h a t m a k e i n t u i t i v e a n d p r a c t i c a l s e n s e m u s t f o l l o w c e r t a i n g u i d e l i n e s a n d processes.

Ideally, a n e e d of s o m e k i n d starts t h e process, a n d a c o m p l e t e d s y s t e m is its result.

A t r a d i t i o n a l S D L C consists o f f o u r f u n d a m e n t a l p h a s e s — p l a n n i n g , analysis, design,

a n d i m p l e m e n t a t i o n ( P A D I ) — w h i c h l e a d t o a d e p l o y e d s y s t e m ( F i g u r e 6.1). T h e sys- t e m i s a cycle b e c a u s e i t i s p o s s i b l e t o r e t u r n t o a n y p h a s e f r o m a n y o t h e r , t h o u g h a n ideal progression is to follow each phase in order. All projects must go through these phases. E a c h p h a s e consists of a series of steps, w h i c h rely on t e c h n i q u e s t h a t p r o d u c e deliverables. W e h a v e a d o p t e d t h e S D L C d e s c r i b e d b y D e n n i s a n d W i x o m (2003). I n T a b l e 6.1, w e s h o w t h e f u n d a m e n t a l p h a s e s , t h e steps, a n d t h e d e l i v e r a b l e s f o r e a c h step. T h e S D L C p r e s e n t a t i o n s e e m s t o b e l i n e a r , b u t a t a n y t i m e t h e p r o j e c t c a n b e

h a l t e d o r c a n r e t u r n t o a n e a r l i e r s t e p i n a n y p h a s e . This a p p l i e s t o W e b s y s t e m d e v e l - o p m e n t a s well, t h o u g h t h e r e a r e s o m e specific issues w h i c h w e discuss later. W e n o w discuss t h e p h a s e s a n d s t e p s ( s e e T a b l e 6.1). I n T a b l e 6.2, w e s h o w t h e s y s t e m d e v e l o p - ment phases and Web impacts.

Ideally, t h e p r o j e c t " f l o w s " d o w n a n d t o t h e right. T h e u p w a r d a r r o w s i n d i c a t e t h a t

C H A P T E R 6 DECISION SUPPORT SYSTEM DEVELOPMENT

F I G U R E 6 . 1 T H E TRADITIONAL SYSTEM DEVELOPMENT LIFE CYCLE

(SDL.C)