Systems
y
Analysis
y and Design
g in a
Changing World, Fifth Edition
4
4
Learning Objectives
D
Describe
ib th
the activities
ti iti off systems
t
analysis
l i
Explain the difference between functional and
nonfunctional system requirements
Describe three types of models and reasons for
creating models
Identifyy and understand the different types
yp of users
who will be involved in investigating system
q
requirements
Systems Analysis and Design in a Changing World, 5th Edition
2
4
Learning Objectives (continued)
Describe
D
ib th
the ki
kind
d off iinformation
f
ti th
thatt iis required
i d tto
develop system requirements
Determine system requirements through review of
documentation interviews
documentation,
interviews, observation,
observation prototypes
prototypes,
questionnaires, joint application design sessions, and
vendor
d research
h
Discuss the need for validation of system
requirements to ensure accuracy and completeness
and the use of a structured walkthrough
Systems Analysis and Design in a Changing World, 5th Edition
3
4
Overview
Analysis phase of SDLC skills needed
z
Fact finding for investigation of system requirements
z
Analyst should learn details of business processes and
daily operations
z
Analyst should become as knowledgeable as business
domain users to build credibility
z
Analyst brings fresh perspective to problem
z
Modeling of business processes based on system
requirements
i
t
Systems Analysis and Design in a Changing World, 5th Edition
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4
The Analysis Phase in More Detail
G th information
Gather
i f
ti
Define system requirements
z
Functional and nonfunctional
Prioritize requirements
Prototype
yp for feasibility
y and discovery
y
Generate and evaluate alternatives
Review recommendations with management
Systems Analysis and Design in a Changing World, 5th Edition
5
4
The Activities of the Analysis Phase
Figure 4-3
Systems Analysis and Design in a Changing World, 5th Edition
6
Activities of the Analysis
y Phase
and Their Key Questions
4
Figure 4-2
Systems Analysis and Design in a Changing World, 5th Edition
7
4
System Requirements
System
S
t
requirements
i
t – specifications
ifi ti
th
thatt define
d fi the
th
new system
Functional requirements
z
Activities system must perform (use cases)
z
Based on procedures and business functions
z
Documented in analysis models
Systems Analysis and Design in a Changing World, 5th Edition
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4
System Requirements (cont)
Nonfunctional requirements
z
Technical requirement – hardware and software
z
Performance requirement – workload measures
z
Usability requirement – user interface, workflow
z
Reliability requirement – outages,
outages error detection
z
Security requirement – access & protection
Systems Analysis and Design in a Changing World, 5th Edition
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4
Models and Modeling
Analyst
A
l td
describes
ib iinformation
f
ti system
t
requirements
i
t
using a collection of models
Complex systems require more than one type of
model
ode
Models represent some aspect of the system being
b ilt
built
Process of creating models helps analyst clarify and
refine design
Models assist communication with system users
Systems Analysis and Design in a Changing World, 5th Edition
10
4
Reasons for Modeling
Figure 4-3
Systems Analysis and Design in a Changing World, 5th Edition
11
4
Types of Models
Differentt types
Diff
t
off models
d l are used
d in
i information
i f
ti
systems development
z
Mathematical – formulas that describe technical
aspects
t off the
th system
t
z
Descriptive – narrative memos, reports, or lists that
describe aspects of the system
z
Graphical
p
– diagrams
g
and schematic representations
p
of some aspect of the system
Systems Analysis and Design in a Changing World, 5th Edition
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4
Some Descriptive Models
Figure 4-4
Systems Analysis and Design in a Changing World, 5th Edition
Overview of Models Used
in Analysis and Design
13
4
Analysis activities named “define system
requirements
requirements”
z
Logical models
z
Provide detail without regard to specific technology
D i models
Design
d l
z
Physical
y
models
z
Provide technical details
z
Extend logical models
Systems Analysis and Design in a Changing World, 5th Edition
14
4
Models
Created
g
During
Analysis
Figure 4-5
Systems Analysis and Design in a Changing World, 5th Edition
Stakeholders—The Source of
System Requirements
People with interest in successful system
implementation
Three p
primary
yg
groups
p of stakeholders
z
Users (use system)
z
Clients (pay for and own system)
z
Technical staff (ensure system operation)
15
4
Every type of stakeholder is identified by analyst
Systems Analysis and Design in a Changing World, 5th Edition
16
Stakeholders Interested
in New System Development
4
Figure 4-6
Systems Analysis and Design in a Changing World, 5th Edition
17
4
More On Users as Stakeholders
Horizontal
Hori
ontal user
ser roles – information flo
flow across
departments
Vertical user roles – information needs of clerical
g
and senior executives
staff, middle management,
z
Business users perform day-to-day operations
z
Information users need current information
z
Management users need summary information
z
Executive users need strategic information
z
External users may have access to system
Systems Analysis and Design in a Changing World, 5th Edition
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4
RMO
Stakeholders
Figure 4-7
Systems Analysis and Design in a Changing World, 5th Edition
19
4
Techniques for Information Gathering
Analysis
A
l i phase
h
d
done tto understand
d t db
business
i
functions and develop system requirements
Original structured approach
z
Create model of existing system
z
Derive requirements from existing system model
Current approach
pp
z
Identify logical requirements for new system
z
Balance the review of current business functions with
y
requirements
new system
Systems Analysis and Design in a Changing World, 5th Edition
20
Relationship Between Information
G th i and
Gathering
d Model
M d lB
Building
ildi
4
Figure 4-8
Systems Analysis and Design in a Changing World, 5th Edition
Themes for Information-Gathering
g
Questions
21
4
Figure 4-9
Systems Analysis and Design in a Changing World, 5th Edition
22
4
Fact Finding Methods
Fact-Finding
Review
R
i
existing
i ti reports,
t fforms, and
d procedure
d
descriptions
Interview and discuss processes with users
Observe and document business processes
B ild prototypes
Build
t t
Distribute and collect questionnaires
Conduct joint application design (JAD) sessions
Research vendor solutions
Systems Analysis and Design in a Changing World, 5th Edition
Review Existing
g Reports,
p
Forms,
and Procedure Descriptions
Source: External industry-wide professional
organizations
o
ga at o s a
and
d ttrade
ade pub
publications
cat o s
Source: Existing business documents and procedure
d
descriptions
i ti
within
ithi organization
i ti
z
Identify
y business rules, discrepancies,
p
and
redundancies
z
Be cautious of outdated material
z
Obtain preliminary understanding of processes
z
Use as guidelines/visual cues to guide interviews
Systems Analysis and Design in a Changing World, 5th Edition
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4
24
4
Sample Order Form for RMO
Figure 4-10
Systems Analysis and Design in a Changing World, 5th Edition
25
4
Conduct Interviews and Discussions with
Users
Effective
Eff
ti way to
t understand
d t d business
b i
functions
f
ti
and
d
rules
Time consuming and resource expensive
May require multiple sessions to
z
Meet all users
z
Understand all p
processing
g requirements
q
Can meet with individuals or groups of users
List of detailed questions prepared
Systems Analysis and Design in a Changing World, 5th Edition
26
Sample
p Checklist to Prepare
p
for User
Interviews
4
Figure 4-11
Systems Analysis and Design in a Changing World, 5th Edition
27
4
Sample
Agenda for
Interview
Figure 4-12
Systems Analysis and Design in a Changing World, 5th Edition
28
4
A Sample Open
Open-Items
Items List
Figure 4-13
Systems Analysis and Design in a Changing World, 5th Edition
Observe and Document Business
Processes
Varies from office walkthroughs to performing actual
tasks
Not necessary to observe all processes at same level
of detail
Mayy make users nervous,, so use common sense
Can document workflows with UML activity diagrams
Systems Analysis and Design in a Changing World, 5th Edition
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4
30
4
Activity Diagrams
Workflow – sequence of steps to process a business
transaction
Activity Diagram – workflow diagram to describe
sequence of steps
Synchronization bar – symbol to control splitting or
merging of a path on an activity diagram
Swimlane
S
i l
– bounded
b
d d area th
thatt contains
t i activities
ti iti off a
single agent
Systems Analysis and Design in a Changing World, 5th Edition
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4
Activity Diagram Symbols
Figure 4-14
Systems Analysis and Design in a Changing World, 5th Edition
32
4
Activity
g
Diagram
that
M d l a
Models
Workflow
Figure 4-15
Systems Analysis and Design in a Changing World, 5th Edition
Activity
y Diagram
g
with Concurrent
Paths
33
4
Figure 4-16
Systems Analysis and Design in a Changing World, 5th Edition
34
4
Build Prototypes
Prototype
Protot
pe - Preliminary
Preliminar working
orking model of a larger
larger,
more complex system component
z
Discovery, design, evolving prototypes
Prototype should be
z
Operative
Working
model to provide “look and feel”
z
F
Focused
d to
t accomplish
li h single
i l objective
bj ti
z
Quick
Built
and modified rapidly with CASE tools
Systems Analysis and Design in a Changing World, 5th Edition
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4
Distribute and Collect Questionnaires
Limited
Li
it d and
d specific
ifi iinformation
f
ti ffrom a llarge number
b
of stakeholders
Preliminary insight into business
Not well suited for gathering detailed information
Closed-ended questions direct person answering
question
Open ended questions encourage discussion and
Open-ended
elaboration
Systems Analysis and Design in a Changing World, 5th Edition
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4
Sample RMO
S
O
Questionnaire
Figure 4-17
Systems Analysis and Design in a Changing World, 5th Edition
Conduct Joint Application
pp
Design
g
Sessions
Expedites investigation of system requirements
Seeks to compress fact-finding, modeling, policy
formation and verification activities into shorter time
formation,
frame
Critical factor is to have all important stakeholders
present
Systems Analysis and Design in a Changing World, 5th Edition
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4
38
4
Joint Application Design Participants
Session leader trained in gro
group
pd
dynamics
namics and JAD
group facilitation
Knowledgeable business and system users and
policy
p
y makers
Technical staff representatives to handle
z
Computer and network configurations
z
Operating environments
z
Security issues
Project team members
Systems Analysis and Design in a Changing World, 5th Edition
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4
Joint Application Design Facilities
Cond cted in special room
Conducted
z
Limit interruptions
p
z
May be off-site
Resources
z
Overhead projector,
projector white board
board, flip charts
charts, work
material
z
Electronic support (laptops)
z
CASE tools
z
Group support systems (GSS)
Systems Analysis and Design in a Changing World, 5th Edition
40
4
A JAD Facility
Figure 4-18
Systems Analysis and Design in a Changing World, 5th Edition
41
4
Research Vendor Solutions
Many problems
M
bl
h
have b
been solved
l db
by other
th
companies
Positive contributions of vendor solutions
z
Frequently provide new ideas
z
May be state of the art
z
Cheaper and less risky
Danger
z
May purchase solution before understanding problem
Systems Analysis and Design in a Changing World, 5th Edition
42
Useful Techniques
q
in Vendor
Research
Technical specifications from vendor
Demo or trial system
References of existing clients
On-site visits
Printout of screens and reports
4
Systems Analysis and Design in a Changing World, 5th Edition
43
4
Validating the Requirements
Make sure
s re gathered information is correct
Structured
St
uctu ed walkthrough
a t oug
z
Effective means of implementing quality control early in
project
z
Verify and validate system requirements
z
Review of findings from investigation and of models
g
based on findings
Project manager responsible for system quality
z
Systems analyst, project manager are partners
Systems Analysis and Design in a Changing World, 5th Edition
44
4
Structured
g
Walkthrough
Form
Figure 4-19
Systems Analysis and Design in a Changing World, 5th Edition
45
4
Summary
Analysis phase activities
z
Gather information
z
Define system requirements
z
Prioritize requirements
z
Prototype for feasibility and discovery
z
Generate and evaluate alternatives
z
R i
Review
recommendations
d ti
with
ith managementt
BPR and Zachman Framework can help
p with the
analysis phase activities
Systems Analysis and Design in a Changing World, 5th Edition
46
4
Summary (continued)
G th i system
Gathering
t
requirements
i
t
z
Functional and nonfunctional
z
Work with various stakeholders (users, clients,
t h i l staff)
technical
t ff)
What kind of information do I need?
z
What are the business processes and operations?
z
How are the business processes performed?
z
What are the information requirements?
Systems Analysis and Design in a Changing World, 5th Edition
47
4
Summary (continued)
Pi
Primary
iinformation-gathering
f
ti
th i ttechniques
h i
z
Review existing
g reports,
p
, forms,, and p
procedure
descriptions
z
Conduct interviews and discussions with users
z
Observe and document business processes
z
Build prototype working models
z
Di t ib t and
Distribute
d collect
ll t questionnaires
ti
i
z
Conduct JAD sessions
z
Research vendor solutions
Systems Analysis and Design in a Changing World, 5th Edition
48
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