This document discusses quality and information systems. It covers the need for software quality assurance, including the challenges of defining user needs and quality. It also discusses software quality measurement and control, the development infrastructure, software process management using methods like the Capability Maturity Model, and participative design. Traditional tools for quality assurance discussed include structured analysis, data flow diagrams, structured design, and flowcharts. The limitations of traditional methods and benefits of object-oriented development and computer-aided software engineering are also summarized.

1. Quality and Information Systems
Panagiotis Kanellis, Επιστημονικός Συνεργάτης Τμήματος Πληροφορικής ΕΚΠΑ
Business Consulting, 377 Syngrou Ave., 175 64 Athens, Greece
Email: kanellis@di.uoa.gr
Δρακούλης Μαρτάκος, Επίκουρος Καθηγητής Τμήματος Πληροφορικής ΕΚΠΑ
Κτίρια Πληροφορικής, Πανεπιστιμιόπολη, 157 84 Αθήνα
Email: martakoσ@di.uoa.gr

2. Talk about:
 The Need for Software Quality Assurance
 Software quality measurement and control
 The Development Infrastructure
 Software Process Management
 Participative Design

3. The Need for Software
Quality Assurance
 The Y2K Problem
 Quality more important than ever as software
becomes an integral part of the products sold
 Defining user needs and judging the quality of
the completed system have proved to be major
challenges
 Meeting specifications does not necessarily mean
quality - there exist numerous factors that
determine the success of a system

4. Maintenance
 Maintenance is the most expensive phase
of the systems development process
 Systems are maintained because of:
 organizational changes
 software complexity
 faulty systems analysis and design

5. What is Quality in IS?
 Any definition of IS quality must be broad in
scope and specific enough to encompass the
satisfaction of user needs. A quality system must
do the following:
 Achieve the business goals articulated by the user
department
 operate at an acceptable cost, commensurate with the
value produced for the firm
 Meet carefully defined performance standards (such as
response time and system availability)
 produce accurate, reliable output with assurance that its
dependability is “good enough” for the purpose
intended
 Be easy to learn and use

6. Means to Ensure Quality
 Use of appropriate systems
development methodology
 Proper resource allocation during
development
 Use of software metrics
 Attention to testing
 Use of quality tools

7. The Role of Methodologies
A collection of methods, one or more for everyA collection of methods, one or more for every
activity within every phase of a developmentactivity within every phase of a development
project. Normally a methodology includes theproject. Normally a methodology includes the
following:following:
 Proven methods for determining and documenting both
system specifications and system design
 programming standards that result in understandable,
maintainable code that is not overly complex
 Guidelines for developing quality measurements to be
agreed on by all interested parties prior to development
 Standards and methods for testing the system
 Software tools to be used at every phase to standardize
the work in the project and to improve the quality of the
output
 Project control methods, including numerous project

8. Resource Allocation
 Determination of how costs, time, and personnel
are assigned to different activities of a systems
development project
 1/4 of a project’s time and cost should be expended in
specifications and analysis
 2/4 should be allocated to design and programming
 1/4 should be allocated to installation and
postimplementation

9. Software Metrics
 Objective assessments of the software
used in a system in the form of quantified
measurements
 Input metrics (educational and experience of
system developers
 Capacity metrics (transaction levels)
 Output metrics (Number of checks printed per
hour)
 Performance/Quality metrics (Number of bugs
per hundred lines of code)
 Value metrics (Business value of a transaction)

10. Traditional Tools and Methodologies for
Quality Assurance
 StructuredStructured Refers to the fact that techniques
are instructions that are carefully drawn up, often
step-by-step, with each step building on the
previous one
Human
Resources
Personnel Benefits Employment
Equal
Economic
Opportunity
Pension
Employee
Savings
Health
Care
Insurance

11. Structured Analysis
Structured AnalysisStructured Analysis Top-down method for
defining system inputs, processes, and outputs
and for partitioning systems into subsystems or
modules that show a logical graphic model of
information flow
 Data Flow Diagram (DFD) Primary tool in structured
analysis that graphically illustrates a system’s
component processes and the flow of data between
them

12. Data Flow Diagrams
Data FlowsData Flows The movement of data between processes,
external entities, and data stores in a data flow diagram
ProcessesProcesses Portray the transformation of input data flows in a
data flow diagram. Each has a unique reference number
and is named with a verb-object phase
Data storesData stores manual or automated inventories of data
External entitiesExternal entities Originators or receivers of information
outside the scope of the system portrayed in the data flow
diagram
Getting down to the lowest level possibleGetting down to the lowest level possible
Data Flow Process Data Store External Entity

13. Structured Design
 Structured DesignStructured Design
Software design discipline,
encompassing a set of
design rules and
techniques for designing a
system from the top down
in a hierarchical fashion
 FlowchartsFlowcharts Describe the
processes taking place
within an individula
program in the system and
the sequence in which
they must be executed
System
Sub-system
Applications
Programs
Modules
Functions
Algorithms
Code

14. Limitations of Traditional Methods
 Slow and unresponsive to today’s fast
changing business world
 It is linear
 Slowness translates into increased cost
 Are process based in contrast to being
data based (The storage of the data is
described as an appentage to those
processes)

15. Object-Oriented Software
Development
 Object-Oriented Software DevelopmentObject-Oriented Software Development
Approach to software development that
deemphasizes procedures and shifts the focus
from modelling business processes and data to
combining data and procedures to create objects
 The system is viewed as a collection of classes
and objects and the relationships between
among them. The objects are defined,
programmed, documented, and saved for use
with future applications
 High reusability, low maintenance costs

16. Computer-Aided Software
Engineering (CASE)
 Computer-Aided Software EngineeringComputer-Aided Software Engineering
(CASE)(CASE) The automation of step-by-step
methodologies for software and systems
development to reduce the amount of repetitive
work the developer needs to do
 Supporting a standard development methodology and
design discipline
 Improving communication between users and design
specialists
 Organizing and correlating design components and
providing rapid access to the via a design repository
 Automating tedious and error-prone portions of analysis,
design, amd code generation

17. Elements of CASE
 Diagramming Tools
 Syntax verifier
 Prototyping tools
 Information repository
 Code generators
 Development methodology
 Project management tools

18. Capability Maturity Model (CMM)
 The CMM is the result of a United
States Department of Defense (DoD)
initiative to improve the
development of military software:
 Cost reduction
 Schedule and quality improvement
 Assessment and evaluation
 Statistical control and measurement
 Certification*

19. The Maturity Levels
Initial
(1)
Repeatable
(2)
Defined
(3)
Managed
(4)
Optimizing
(5)
Disciplined
Process
Standard,
Consistent
Process
Predictable
Process
Continuously
Improving
Process

20. CMM Structure
Maturity
Levels
Key Process
Areas
Common
Features
Key
Practices
contain
organized by
contain
Process Capability
Goals
Implementation or
Institutionalization
Infrastructure or
Activities
indicate
achieve
address
describe

21. Advantages of CMM
 The advantages of CMM are argued
to be:
 Risk reduction
 Cost and schedule adherence
 Improved quality
 Improved communication and customer
satisfaction

22. Potential Limitations of CMM
 Several potential limitations may also be
noted (non-exhaustive list):
 Effort and cost involved in
implementation (v size)
 Tends to ignore the ‘unique’ aspect of
projects
 Validity of scale and maturity
questionnaire
 Application of assessment/evaluation
method

23. What you really need...
“…few people in industry know what
constitutes a system. Many people
think machinery and data processing
when I mention systems. Few of
them know that requirement,
training, supervision and aids to
production workers are part of the
system.”
Deming (1989)

24. A Quality Oriented Organizational
System [Ravichandran and Rai, MISQ (forthcoming)]
Leadership Structure Process Outcome
Top Management
Leadership
Management
Infrastructure
Sophistication
Process
Management
Efficacy
Quality
Performance
Stakeholder
Participation