Chapter 14 - Information Systems Development
What is the System Development
Life Cycle?
What is an information system (IS)?
° A set of hardware, software, data, people, and
procedures that work together to produce information
° Supports daily, short-term, and long-range activities
of users
What is the system development life
cycle (SDLC)?
° A set of activities developers use to build an
information system
° Used to guide system developers
• Through development of systems
• To maintain and monitor ongoing activities
° Sometimes referred to as software engineering
What are the phases in the SDLC?
What
are guidelines for system development?
° Group activities or tasks into phases
• Number of phases can vary
• Terminology can vary
° Involve the users
• Anyone for whom the
system is being built
° Develop standards
• Sets of rules and
procedures a company
expects employees to
accept and follow
• Helps people working on the same project produce
consistent results
Who
participates in the system development life cycle?
° Should involve representatives from each department in
which the proposed system will be used
What is a systems analyst?
° The users’ primary contact person
° Responsible for designing and developing an
information system
° Liaison between the users and the IT professionals
° Converts user requests into technical specifications
What is the project team?
° A team formed to work on a project from beginning to
end
° Consists of users, the systems analyst, and other IT
professionals
What is project management?
° The process of planning, scheduling, and then
controlling the activities during the SDLC
° Goal is to deliver an acceptable system to the user in
an agreed-upon time frame, while maintaining costs
° Must identify and record items for the project plan
What is a Gantt chart?
° A popular tool used to plan and schedule the time
relationships among project activities
° Developed by Henry L. Gantt
° A bar chart that uses horizontal bars to show project
phases or activities
What is project management
software?
° Assists in planning, scheduling, and controlling
development
projects
What is feasibility?
° A measure of how suitable the development of a system
will be to the company
° Must frequently be re-evaluated during the SDLC
° Four tests to evaluate feasibility of a project
What is documentation?
° The collection and summarization of data and
information
° Includes reports, diagrams, programs, or any other
deliverable generated during the SDLC
What are six data and information
gathering techniques?
° Project team members gather data and information
What
is a joint-application design (JAD) session?
° A lengthy, structured, group work meeting where users
and IT professionals discuss an aspect of the project
° Goal is to
obtain group
agreement
on an issue
What are some research sources?
° Newspapers, computer magazines, reference books, and
the Web
Company on the Cutting Edge
Ziff
Davis Media
° The leading information authority for buying, using,
and experiencing technology and the Internet
° Largest technology and Internet magazine publisher in
the United States
° Publishes many industry-leading consumer and business
publications
What
Initiates the System Development Life Cycle?
What
are some reasons to create or modify an information system?
What is an informal project
request?
° A user may request a new or modified information
system verbally in a telephone conversation or written as an e-mail message
What is a request for system
services?
° Also called a project request
° Users write a formal request for a new or modified
information system
° The document becomes the first item in the project
notebook
Case Study – Web Lane Café
° The Web Lane Cave is a cybercafé,
a coffee house or restaurant that provides Web access to its customers
° It is a worldwide chain of cybercafés
with locations in 40 cities around the world
° Staff members can provide assistance; training courses
provided for beginning computer users
° Cafes use the latest hardware and software
° It provides 30 minutes free computer/Web access with
each beverage or snack purchased; additional time can be purchased for $5.00
per hour
Case Study – Web Lane Café
° Started operations in 1995 and now serves thousands of
customers
° The Web site has hundreds of hits a day
Case Study – Web Lane Café
° CEO John Simmons
° Computers and equipment are provided without charge by
vendors to showcase their products; customers directed to vendor’s online
storefront for purchases
° Vendors request information from Carla Rosatti, the marketing manager; the number of requests is
rising quickly
° Carla would like to add the vendor information to the
Web to save time and money
Case Study – Web Lane Café
° Carla sends an e-mail message to the vice president of
information systems
Case Study – Web Lane Café
° He agrees and tells her to fill out a Request for
System Services form and submit it to Mohammed Hossain,
chair of the steering committee
Planning Phase
What is the planning phase?
° Begins when the steering committee receives a project
request
° Four major activities are performed
• Review and approve the project requests
• Prioritize the project requests
• Allocate resources such as money, people, and
equipment to approved projects
• Form a project development team for each approved
project
Case Study – Planning at Web Lane
Cafe
° Mohammed Hossain distributes
the project request to all members of the steering committee
° Carla Rosatti is invited to
the steering committee meeting to discuss the project request
° The steering committee decides the project request
identifies an improvement; potential for considerable savings for the company with
benefits for vendors
° The request is approved
° Tyrone Greene, vice president of information systems,
assembles a system development team
° Sadie Lapinski, senior
systems analyst, assigned as project leader
Analysis Phase
What is the analysis phase?
° Consists of two major tasks
What is the preliminary
investigation?
° Sometimes called the feasibility study
° To decide whether the problem or improvement in a
project request is worth pursuing
° The system analyst conducts a very general study of
the project
What
is a feasibility report?
° Also sometimes known as the feasibility study
° A report used to present the findings of the
preliminary investigation
° Contains five major sections
• Introduction
• Existing system
• Benefits of a new system
• Feasibility of a new system
• Recommendation
Case
Study – Analysis: Preliminary Investigation at Web Lane Cafe
° Sadie Lapinski, senior
systems analyst, meets with Carla Rosatti to discuss
the project
° Sadie interviews the controller, Mohammed Hossain, to obtain some general cost and benefit figures
° She calls a vendor
° She prepares the feasibility report
° The team members review the report and Sadie submits
it to the steering committee
° The report recommends continuing into the detailed
analysis phase
° The steering committee agrees
What is a detailed analysis?
° Sometimes called logical design
° Involves three major activities
° The proposed solution is developed without regard to
any specific hardware or software
What is structured analysis and
design?
° A technique that attempts to address a problem by
using graphics and other tools
° Used to document findings in a way than can be
understood by everyone
Technology Trailblazer
Ed Yourdon
° Recognized as one of the 10 Influential Men and Women
of Software
° Noted for developing the method of object-oriented
systems analysis and design
° Author of more than two-dozen computer books and 200
technical articles
° Publishes a weekly
e-zine, The Yourdon
Report, and an informative Web site
What
is an entity-relationship diagram (ERD)?
° Also called an E-R diagram
° A tool that
graphically
shows the
connections
between
entities in a
system
What is a data flow diagram (DFD)?
° A tool that graphically shows the flow of data in a
system
What is a context diagram?
° A DFD that identifies only the major processes
• DFDs are prepared on a level-by-level basis
• Lower level
DFDs add
detail and
definition to
the higher
levels
What is a project dictionary?
° Sometimes called the repository
° Contains all the documentation and deliverables of a
project
° Helps keep track of the huge amount of details in a
system
° One section explains every item found on the diagrams
° A variety of techniques used to enter items in a
project dictionary
What is structured English?
° A style of writing that describes the steps in a
process
° Used to explain details of a process in the project
dictionary
What is a decision table?
° A table that lists a variety of conditions and the
actions that correspond to each condition
° Used when a process consists of many conditions or
rules
What is a decision tree?
° A diagram that shows conditions and the actions
graphically
° Used when
a process
consists of
many
conditions
or rules
What is a data dictionary?
° Each data item has an entry in the data dictionary
° Stores the data item’s name, description, and other
details about each data item
What is the system proposal?
° Used to assess the feasibility of each alternative
solution
° Recommends the most feasible solution for the project
° Systems analyst presents the system proposal to the
steering committee for approval
° If approved, the project enters the design phase
What is packaged software?
° Sometimes called commercial off-the-shelf software
° Pre-written software available for purchase
° Available for different types of computers
° Two types of packaged software
How
can you locate software vendors?
° Search for names and vendors on the Web by entering
your requirement as the search criteria
° Read computer magazines and trade publications
• A magazine written for a specific business or industry
What is custom software?
° Application software developed by the user or at the
user’s request
° Used when a company cannot find a package that meets
all its needs
° Matches the company’s requirements exactly
° Usually more expensive and takes longer to design and
implement than packaged software
Case
Study – Detailed Analysis at Web Lane Cafe
° Team gathers data and information by interviewing
employees and vendors and observing marketing staff
° Team prepares documents to record their findings
° Documents become part of the project notebook
° After two months of study, Sadie discusses findings
with supervisor, Tyrone Greene
° Sadie recommends their Web site include a link to
Vendor Information
° Tyrone writes a system proposal for the steering
committee to review
° Tyrone recommends that Jesse Martinez, Webmaster,
modify the Web site in house
° Also recommends that the Web Lane Café invest in a
larger database server
° The steering committee agrees and the design phase
begins
Design Phase
What is the design phase?
° Consists of two major activities
• If necessary, acquire hardware and software
• Develop all of the details of the new or modified
information system
° Systems analyst often performs these two activities at
the same time
What
is needed to acquire new hardware and software?
° Identify all the hardware and software requirements of
the new or modified system
° Summarize the requirements for potential vendors
What is an e-zine?
° An electronic magazine
° A publication available on the Web
° By using
the Web,
the systems
analyst can
locate
information
more quickly
and easily
than in the
past
What
are three basic documents used to summarize technical specifications?
° Documents are used to summarize requirements for
vendors
What is an online product catalog?
° A catalog on the Web that provides up-to-date and easy
access to products, prices, specifications, and ordering information
° One way to locate vendors
What is a value-added reseller
(VAR)?
° A company that purchases products from manufacturers
and then resells these products to the public
° Offers additional services with the product
• User support, equipment maintenance, training,
installation, warranties
° Most manufacturers have requirements that the VAR must
meet
What is a turnkey solution?
° A complete system provided by a VAR
° Advantage of a full-service VAR is you deal with only
one company for an entire system
What
is involved in testing and evaluating vendor proposals?
° Vendors respond to RFQs and RFPs with completed quotations and proposals
° System analysts evaluate the proposals and select the
best one
° After rating the proposals, the systems analyst
presents a recommendation
to the steering committee
Where can you find a demonstration
copy?
° Vendors may provide a copy
° Some vendors allow you to download or run a
demonstration copy directly from their Web site
What
is an end-user license agreement (EULA)?
° Gives you the legal right to use software under
certain terms and conditions
° When you purchase software, you do not own it
° Most license agreements include restrictions
• Software used on one computer by one user
• Restrictions on copying the software, modifying it, or
translating it to another language
Case
Study – Design: Hardware Acquisition at Web Lane Cafe
° Sadie and her team compile a requirements list for the
database server
° They prepare an RFP and submit it to 12 vendors
° They get 10 replies
° Development team selects 2 to evaluate
° Team members research the two servers, and select the
best one
° Sadie summarizes findings in a report to the steering
committee
° Committee gives authorization to award a contract
° Sadie informs all 12 vendors of the decision
What is detailed design?
° Sometimes called physical design
° Develop detailed design specifications for the
components in the proposed
solution
° Specifies
hardware and software for automated procedures
What is database design?
° The system analyst builds upon the data dictionary
developed during the analysis phase
° Should represent accurately the data requirements of
the company
° Identifies those data elements that currently exist
within the company and those that are new
What is input and output design?
° The systems analyst carefully designs every menu,
screen, and report specified in the requirements
° Outputs usually are designed first because they help
define the requirements for the inputs
° A mockup
is a sample
of the
input or
output that
contains
actual data
What is a layout chart?
° Designed after the mockup is approved by users
° More technical
° Contains programming-like notations for the data items
What is program design?
° Systems analyst identifies the processing
requirements, or the logic, for each program in the system
° Prepares the program specification package which
communicates program requirements clearly to the programmer
What is a systems flowchart?
° Documents relationships among programs in a process
° Shows how other elements of the system interact with a
major process
What is a prototype?
° A working model of the proposed system
° Systems analyst actually builds a functional form of
the solution during design
° Users work with the system to make sure it meets their
needs
° Once users approve a prototype, system developers
implement a solution
° The systems analyst often can convert the working
model to the actual solution
What
is computer-aided software engineering (CASE)?
° Software tools designed to support one or more
activities of the SDLC
° Used to increase the efficiency and productivity of
the product development team
What is an integrated CASE product?
° Some CASE tools exist separately
° Others are integrated
• Called
I-CASE or a CASE workbench
Company on the Cutting Edge
Visible Systems Corporation
° Developer of Visible Systems Corporation's Visible
Advantage™, an enterprise architecture and data warehouse development CASE tool
° Another product is Visible Analyst®, an
I-CASE tool that provides graphical analysis and design resources for
applications and database designs
Design Phase
What are quality review techniques?
° A structured walkthrough, a step-by-step review of any
SDLC deliverable
° Used to review the detailed design specifications
before they are given to the programming team
° Review process should include users, the senior
systems analyst, and members of the project team
Case
Study – Detailed Design at Web Lane Cafe
° Sadie and her team begin designing the Vendor Web
System
° They study current vendor information and conduct more
interviews
° They make changes to the company’s database, Web site,
and the associated programs
° They prepare documents
° They meet with users and IT personnel to walk through
the deliverables
° They locate and correct errors
° They present the design to the steering committee
° Committee agrees with the design solution and consents
to implement it
Implementation Phase
What is the implementation phase?
° Purpose is to construct, or build, the new or modified
system and then deliver it to the users
What
is the program development life cycle (PDLC)?
° Programmers write programs from the program
specification package created during analysis
° Follow an organized set of activities known as the
PDLC
° Six steps
What
are the three types of tests performed by system developers?
What is training?
° Involves showing users exactly how they will use the
new hardware and software in the system
° Could be one-on-one sessions or classroom-style
lectures
° Users should practice on the actual system during
training
° Users
should
receive
user
manuals
for
reference
What are conversion strategies?
° Strategies used to change from the old system to the
new system
What is direct conversion?
° The user stops using the old system and begins using
the new system on a certain date
° Also called an abrupt cutover
What is parallel conversion?
° Consists of running the old system alongside the new
system for a specified time period
° Results from both systems are compared
° If positive, the old system is terminated abruptly or
phased out
What are other types of conversion?
° Phased conversion
• Used for larger systems that have multiple sites Also called location conversion
• Each site converts at a separate time using either
direct or parallel conversion
° Pilot conversion
• Only one location in the company uses the new system
so it can be tested
• Once the pilot site approves the new system the other
sites convert using one of the other conversion strategies
Case
Study – Implementation at Web Lane Cafe
° Sadie receives the program specification package
° Sadie forms an implementation team
° The team works together to implement the Vendor Web
System
° They answers questions about the design
° Sadie tests the finished design
° She arranges a training class for the employees
° She gives each attendee a user guide
° Sadie sends a letter to all existing vendors informing
them when the new service will be available and how to use it
Technology Trailblazer
Tom DeMarco
° Has explored the successes and the absurdities of the
software development process in over 100 books, articles, and papers
° Focuses on productive business principles for project
management
° A principal of the Atlantic Systems Guild, Inc., a
software think tank exploring issues facing the computer industry
° Believes that good managers focus on motivating
employees and designing organizations to work efficiently
Support Phase
What is the support phase?
° Provides ongoing assistance for an information system
and its users after the system is implemented
° Four major activities
What
is a post-implementation system review?
° A meeting with users
° Purpose is to find out if the information system is
performing according to the users’ expectations
° May identify errors that are corrected
° Can identify system enhancements
• Involve modifying or expanding an existing application
system
° Performance monitoring used to determine if the system
is inefficient at any point
Case Study – Support at Web Lane
Cafe
° Sadie holds a post-implementation system review
° She obtains feedback
° Carla wants to add new information
• Carla fills out a Request for System Services
• The request is added to agenda of the next steering
committee meeting
• The SDLC process starts again
Summary of Information Systems
Development
° What is the system development life cycle?
° What initiates the system development life cycle?
° Planning phase
° Analysis phase
° Design phase
° Implementation phase
° Support phase
Chapter 14 Complete