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
4
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
8
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
9
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
12
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
18
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
23
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
29
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
31
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
35
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
36
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
37
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
39
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