Title: Solving Problems in IS: Systems Approaches
1Solving Problems in IS Systems Approaches
- Logical framework in which to work.
- Serves as a reminder. Did I forget anything?
2The Systems Development Life Cycle, SDLC
Planning
Analysis
Design
Implementation
3The Systems Development Life Cycle, SDLC
Planning
Analysis
Design
Implementation
Maintenance!
4The Systems Development Life Cycle
Systems Investigation Product Feasibility Study
Understand the Business Problem or Opportunity
(Dennis text 4 phases, with Investigation named
Planning)
Systems Analysis Product Functional Requirements
Develop an Information System Solution
Systems Design Product System Specifications
Systems Implementation Product Operational System
Implement the System Solution
Systems Maintenance Product Improved System
5SDLC
Identify Problem/Value. Feasibility
Analysis. Project Management.
Understand as-is system. Identify
Improvements. Develop concept for the to-be
system. Use Cases. DFDs. ERDs.
Planning
Analysis
Develop technical specifics for
to-be system. Design Strategies. Physical
DFD. Physical ERD. Infrastructure Plan. Interface
Structure. Interface Standards. Interface
Template. Interface. Evaluate.
Construction (programming) Testing Documentation C
onversion Change Management Support Installation
Design
Implementation
6Watch out for runaway computer systems!
- 2-4 times over budget.
- 2-3 times behind schedule.
- Not performing as expected.
- Complicated to use.
- Requires more and more users to operate.
- Loses or destroys data.
730-35 of computer projects are runaways!
(Dennis text 42 of all corporate Projects are
abandoned)
8Where can we spot one?
Planning
Analysis
Design
Implementation
Maintenance
9Where can we spot one?
Planning
Analysis
Design
On time? Budget?
Implementation
Maintenance
10Where can we spot one?
Planning
Analysis
Design
On time? Budget?
Implementation
Performing as expected? What do the users think?
Maintenance
11How can we prevent runaways?
Planning
Analysis
Design
Implementation
Maintenance
12How can we prevent runaways?
The number one cause of runaways is the
installation or expansion of a computer system
when management does not know what the automation
is meant to accomplish.
Planning
Analysis
Design
Implementation
Maintenance
13How can we prevent runaways?
Involve both management and users in specifying
what the system needs to accomplish.
The number one cause of runaways is the
installation or expansion of a computer system
when management does not know what the automation
is meant to accomplish.
Planning
Analysis
Design
Continuously talk to and monitor the design team.
BUT, dont use them as your only source
of information!
Implementation
Maintenance
14How can we prevent runaways?
Involve both management and users in specifying
what the system needs to accomplish.
Planning
Analysis
Design
Test early and often!
Continuously talk to and monitor the design team.
BUT, dont use them as your only source
of information!
Implementation
Watch to make sure things are going smoothly.
Maintenance
15CONFIRM A classic runaway example.
- AMR partnered with Budget, Hilton, and Marriott
to leverage the success of SABRE, Americans
reservation system. - SABRE auditors, two months before the project was
supposed to go on-line, concluded that the
project was at least 18 months from completion. - Budgeted at around 125 Million... around 225
Million shelled out with no result.
16Where did CONFIRM go wrong?AMRs answer
Planning
Analysis
Design
Implementation
Maintenance
17Where did CONFIRM go wrong?AMRs answer
Planning
Analysis
Budget, Hilton, and Marriott assigned individuals
who lacked knowledge of the industry.
Design
Implementation
Maintenance
18Where did CONFIRM go wrong?AMRs answer
Planning
Analysis
Budget, Hilton, and Marriott assigned individuals
who lacked knowledge of the industry.
These individuals failed to specify what they
wanted from the system.
Design
Implementation
Maintenance
19Where did CONFIRM go wrong?Budget, Hilton, and
Marriotts answer
Planning
Analysis
Design
Implementation
Maintenance
20Where did CONFIRM go wrong?Budget, Hilton, and
Marriotts answer
Planning
Schedules overly optimistic.
Analysis
You said SABRE experts would be assigned to
this project... where are they?!
Design
TECHNICAL PROBLEMS!! The two 3090s didnt
connect well.
Implementation
Maintenance
21Where did CONFIRM go wrong?Budget, Hilton, and
Marriotts answer
Planning
Schedules overly optimistic.
Analysis
We GAVE you specs... 6 feet high!
You said SABRE experts would be assigned to
this project... where are they?!
Design
Endless delays. Cost overruns. PROBLEMS CONCEALED!
Implementation
Maintenance
22Software Development...
- ... is hard!
- Windows 95
- 400 people
- 4 years
- 100,000,000
- 10,000,000 lines of code
- 1 person meeting per line of code
23- Studies have indicated that an experienced
programmer can produce 30 lines of code per day
on average. - A new billing system can easily require 1 million
lines of code. - Thats 33,000 days, or 133 years, for one
programmer! Coordinating multiple programmers
makes the job more complex. - Annual software productivity increases - about 4
per year (vs. 30 in hardware).
24The IS Project Logjam
- Two years planned to put water and
electricity on the same bill. 40 man-years and
2 million later, no results! - Why is software development so difficult?
25The IS Project Logjam
- Government study two-thirds of software
projects had no formal procedure for estimating
the amount of labor or code required, and nearly
half had no standard way to predict the cost of a
program. - Late additions and maintenance - 80 of software
budgets. - Twice the time expected, twice the money -
runaway. As noted, 30-35 of companies fall
victim to them.
26Breaking the IS Project Logjam - Solution
- Give data-processing departments the same clout
as everybody else. - Keep both managers and ultimate users involved in
every step of software development. - Make data-processing managers periodically work
side by side with software users. - Break up big projects to keep programming teams
small. - Give programmers elbowroom.
- Make existing software easier to maintain.
27Have competent Project Managers and Analysts!!!!
28Development Methodologies
- Traditional (structured)
- Waterfall - sequential through steps.
- Parallel - sequential through steps, with
Design often being done in multiple
simultaneous subprojects. - Rapid Application Development (RAD)
- Phased - system broken into versions, steps are
completed for each version and repeated for next
version. - Prototyping - quick and dirty through Analysis,
Design, and Implementation in iterative fashion. - Throwaway Prototyping - same as above except
prototypes are pretend.
29Waterfall Development Method
30Pros and Cons of the Waterfall Method
Pros
Cons
Identifies systems requirements long before
programming begins
Design must be specified on paper before
programming begins
Long time between system proposal and delivery
of new system
31Parallel Development Method
32Pros and Cons of Parallel Development
Pros
Cons
Reduces Scheduled Time
Still Uses Paper Documents
Less Chance of Rework
Sub-projects May Be Difficult to Integrate
33How Prototyping Works
34Throwaway Prototyping
35Pros and Cons of Prototyping
Pros
Cons
Very quickly produces a system
Less disciplined - Often sloppy
Increased and Quicker user interaction
Initially intelligent design features Become
problems
36Picking the right methodology