Systems Development Lifecycle (EXAM #2)

Question 1

Systems Development Lifecycle (SDLC)

Answer 1

-process of developing software or information systems from start to finish

Question 2

SDLC Phases

Answer 2

1. planning
2. analysis
3. design
4. development
5. testing
6. implementation
7. maintenance

Question 3

1. Planning

Answer 3

a. the systems development team makes a plan for the systems development project. during this phase it is vital to conduct several types of feasibility analyses in order to assess whether developing the system is a good idea
b. main actors: project manager, project sponsor (usually VP or other high level manager), senior analysts
c. end result is a formal approval (usually signed off by management) that the project will move forward and high-level requirements matrix

Question 4

requirements matrix

Answer 4

list of approved features and key characteristics of the new system that are required for success

Question 5

feasibility analyses

Answer 5

• technical
• economical
• legal
• operational
• scheduling

Question 6

technical feasibility

Answer 6

is the system realistic, and we have the expertise to develop it?

Question 7

economical feasibility

Answer 7

do benefits exceed costs?

Question 8

legal feasibility

Answer 8

does the system meet all regulations and laws?

Question 9

operational feasibility

Answer 9

will our organization be able to operate the system

Question 10

scheduling feasibility

Answer 10

is the project timeline realistic given our resources

Question 11

2. Analysis

Answer 11

a. one of the key tasks is to determine user requirements (want do they want the system to be able to do)
- users can be: customers, clients, own organization, or other stakeholders (called requirement gathering or requirement elicitation)
- then compiled in a requirements definition document

b. main actors: system analysts & business analysts

Question 12

requirements definition document

Answer 12

more detailed version of the requirements matrix

Question 13

3. Design

Answer 13

a. the system is laid out using mockups, and the basic modules and logic for the software portion of the system are outlined
- example screens and windows are developed (like storyboarding) to illustrate basic flow and feel of the system
- hardware requirements are also determined during this phase

b. main actors: project manager, system architect, programmers (support role, not programming), and users (to give input and advice)

Question 14

4. Development (Construction)

Answer 14

a. where actual programming takes place. the primary deliverable during this phase is a prototype or “alpha” system that can then be tested for quality assurance
- testing is actually begun during the development stage and are performed together

b. main actors: programmers, testers

Question 15

5. Testing

Answer 15

a. users try out the system, find bugs, and see if they can break it and provide feedback to the development team in order to refine the system
- testers have to be creative and try to break into the system (system penetration testing or white hat)

b. main actors: testers, programmers

Question 16

Types of testing:

Answer 16

• unit
• integration
• system
• user acceptance

Question 17

unit testing

Answer 17

do individual components of the code work properly?

EX: if i click “submit” does my information get stored?

Question 18

integration testing

Answer 18

test whether individual units work together properly

Question 19

system testing

Answer 19

does the entire system of groups of units work properly, occurs after integration

Question 20

user acceptance testint

Answer 20

doe the end user actually use this system the way it is intended, in a manner that allows them to perform their job successfully and will be continually followed by the user after nobody is looking over them

Question 21

6. Implementation

Answer 21

a. when the system is ready to be delivered to the users/customers to “go live” - handle real transactions
- must train users how to use the new system

Question 22

Approach to implementation

Answer 22

direct conversion
parallel conversion
phased conversion
pilot conversion

Question 23

direct conversion

Answer 23

switch from the old system to the new one “overnight”

Question 24

parallel conversion

Answer 24

continue to run the old system until the new one is activated & working

Question 25

phased conversion

Answer 25

activate the new system one module at a time

Question 26

pilot conversion

Answer 26

activate and test the new system in one branch of an organization, then implement it in other branches once the pilot branch has figured out all the bugs

Question 27

7. Maintenance

Answer 27

a. includes support for the system even after implementation
- if an error is discovered, the development team will fix it
- if new features are requested, the development team can negotiate for developing the new features

Question 28

make

Answer 28

the organization will write the software code - or some portion of it - themselves using their own programmers

Question 29

build

Answer 29

organization will fire an external consulting company to build the system, or some portion of it, for them

Question 30

buy

Answer 30

the organization will buy some off the shelf software to meet their needs

Question 31

Consider Advantages/Disadvantages

Answer 31

1. availability of commercial packages
2. availability of competent personnel
3. risk of losing sensitive information

-if not unique, most likely a “commercial off the shelf” (COTS) package

Question 32

SDLC Methodologies

Answer 32

• waterfall

- agile

Question 33

waterfall

Answer 33

moves through each of seven phases above in linear, step order fashion in which each phase is executed only once in its entirety

pros: low cost, if everything goes right
cons: if you get to user acceptance and it’s clear the system isn’t going to work back to the beginning

therefore, if a) you expect your requirements to change over time for whatever reason b) can’t adequately gather your requirements in a single effort then consider agile

Question 34

agile

Answer 34

approaches such as rapid application development (RAD), and Extreme programming (XP) approaches iterate repeatedly through frequent design/develop/test/redesign cycles in order to prototype as often as possible to quickly work out kinks and bugs

Question 35

quality constraints

Answer 35

These three variables are interdependent
You cannot change one without changing the others
For example, decreasing a project’s timeframe means either increasing the cost of the project or decreasing the scope of the project to meet the new deadline
Increasing a project’s scope means either increasing the project’s timeframe or increasing the project’s cost – or both – to meet the increased scope changes
Project management is the science of making intelligent trade-offs among time, cost, and scope

Question 36

Reasons for Systems Development Problems

Answer 36

• Important Business Requirements Unclear or Missing
• Skip SDLC Phases
• Failure to Manage Project Scope
• Poor project management
• Changing Technology

Question 37

Principles of Successful Development

Answer 37

• Keep the Budgets small
• If it doesn’t work, kill it
• Keep requirements to a minimum
• Test and Deliver Frequently
• Assign NON-IT execs to software projects
• [Ask the “dumb” questions]