Transcript Document 7205576
CSE3308/DMS/2004/3
Software Engineering: Analysis and Design - CSE3308
David Squire David.Squire@csse.monash.edu.au
Room 134, Building 75, Clayton 9905 8307 Room 5.23A B Block, Caulfield 9903 1033 (thanks to Martin Dick for initial development of unit resources) CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.1
Lecture Outline
Unit Outline
What is Software Engineering?
Why Bother with Software Engineering?
Product and Process CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.2
Unit outline
Objectives
Assessment
Passing the unit
Lectures, practice classes, the lecturer and consultation
Recommended reading
Assignment work
Web pages CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.3
Objectives (1)
Knowledge of the difficulties of specifying and producing large software products, leading to
an appreciation of the need for software engineering methodologies
understanding of the distinction between software engineering and programming, and thus the distinction between a software configuration and a program
An understanding of, and ability to apply, the methods of analysis and design, including:
structured analysis and design using Yourdon notation
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Context Diagram, Event Lists, Data-Flow Diagrams, Entity-Relationship Diagram, State Transition Diagrams, Process Specifications, Data Dictionary, Structure Chart
object-oriented analysis and design using UML
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Use Cases, Class Diagrams, Interaction Diagrams, State Diagrams, Package Diagrams, Activity Diagrams CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.4
Objectives (2)
Knowledge of , and the ability to apply, principles of user interface design such as affordances, awareness of mental models, visibility, mapping and feedback.
An awareness of the problems of managing large software development projects, and the techniques used to address them, including
Configuration management
Software metrics
Validation and verification techniques
Quality management CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.5
Assessment and Passing
There are two assessment components:
An examination worth 40% of the marks
Assignments worth 60% of the marks There will be two practical assignments:
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A group project worth 45%
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An individual assignment worth 15%
You need to achieve 50% in both the exam and the assignments and achieve an overall mark of 50%, i.e.
You must get at least 20 marks out of 40 for the exam
You must get 30 marks out of 60 for the assignments
You must get 50 marks out of 100 overall CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.6
Lectures
Lectures will be held at:
2:00pm on Wednesdays, room S6
2:00pm on Thursdays, room C1
Lecture slides for each week will be made available on the unit web site
Lecture slides are
not you
“lecture notes”. Notes are what write during lectures.
All lecture material, worksheets and assignment work is examinable
It is your responsibility to ensure that you have copies of all such materials
CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.7
Practice Classes
There will be two practice classes each week:
12.00 noon to 2:00pm Thursday, room EH2
11:00am to 1:00pm Friday, room EH2
Students are expected to attend at most one practice class per week
During a practice class, students are expected to work on practice problems and/or activities, which will be distributed via the unit web site, or on their assignments
The lecturer and tutors will be available to comment on, and help with, solutions during the practice class.
Practice classes start in week 2 CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.8
Lecturer and Consulation
Lecturer: David Squire Office: Clayton, Bldg. 75, Room 134, Ph. 9905 8307 (mostly Tue, Wed, Thu & Fri, 1st semester) Caulfield, Bldg B, Room 5.23A, Ph. 9903 1033 Email: David.Squire@csse.monash.edu.au
Web: http://www.csse.monash.edu.au/~davids/
Consultation
The primary time for consultation is during the practice classes
Other consultation at Clayton campus: Wednesday 3:15pm - 5pm, building 75, room 134
Preference will be given to students who make appointments.
In time of high demand, preference will be given to students who did not have an appointment during the previous week.
CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.9
Recommended Reading
There is no prescribed text. The following books cover the basic material in the unit:
Booch, G., Rumbaugh, J., and Jacobson, I. The Unified Modeling Language User Guide (1998)
Yourdon, E.: Modern Structured Analysis (1989)
Pressman, R., Software Engineering: A Practitioner's Approach, (2000)
The lecture slides are long and detailed - the intention is to give you the material you will need
A list of further useful books is provided in the Unit Outline. Copies of these books are on reserve in the library.
CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.10
Assignment work
All work submitted by a group must be solely the work of that group
All work submitted by an individual must solely be the work of that individual
This is not to mean that you may not consult with others, but: If you receive any help, you must specifically acknowledge that person in your submitted work
If any student or group of students submits work which is not their own, they will be disciplined according to the University and Faculty policies - see the unit web site
Penalties range from exclusion from University to zero marks for the unit CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.11
Assignment work (2)
Extensions
If you believe that your assignment will be delayed because of circumstances beyond your control, you must apply for an extension
before
the due date
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Medical certificates or certification supporting your application may be required
Contributions to group work
Group members will rate the contributions of all other members
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these ratings will modify the mark that each individual receives, but not by more than 20%.
If a group is having trouble with an individual member and is unable to resolve the problem themselves:
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the group
must
approach the lecturer to assist in resolving the problem
as soon as it arises
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A claim that a student did not contribute his or her fair share
will not be considered
if it is made just prior to the submission of the assignment, or after submission CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.12
Web site
The unit web site can be found at: http://www.csse.monash.edu.au/courseware/cse3308/
Information at the web site will include:
Lectures slides
Assignment specifications
Resources and links relevant to the unit
Anonymous feedback forum
You should check the unit web site each week CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.13
What is Software Engineering?
Group Exercise
Break into groups of 4 or 5 (i.e. your neighbours, don’t move around the theatre)
Take 5 minutes to write down a definition of software engineering - this can be in point form
After 5 minutes, we will collect definitions from the class CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.14
What is Software Engineering?
Many Definitions
“… the establishment and use of sound engineering principles in order to obtain economically software that is reliable and works efficiently on real machines.” (Bauer 1969)
“The application of science and mathematics by which the capabilities of computer equipment are made useful to man via computer programs, procedures, and associated documentation.” (Boehm 1981)
“The application of a systematic, disciplined, quantifiable approach to the development, operation and maintenance of software; that is the application of engineering to software.” (IEEE 1993)
Designing, building and maintaining large software systems in a cost-effective way.
CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.15
Why bother with Software Engineering?
Many very successful projects don’t use software engineering, e.g.
early Microsoft
ID Software’s Doom
Sausage’s Hotdog
BUT they are often not repeatable Many more projects fail because they don’t use software engineering. Failures occur because:
of the size of the project relative to previous efforts
key personnel have left
of failure to understand requirements
the project delivers, but lacks the required quality
of the introduction of new technology
of many, many other reasons CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.16
Some classic disasters
CS90 - How Westpac wasted $150 million
Therac-25 - Radiation death courtesy of the computer McKinsey’s PeopleNet
New Jersey Department of Motor Vehicles Microsoft’s first Windows database - Omega
Australian Customs Service - Intelligence Gathering System
Denver International Airport
London Ambulance Service CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.17
From E-Trade to E-Grave
3rd largest on-line stockbroking service in the world
60,000 trades a day
February 3rd, 1999 - 75 minutes downtime after slow access
February 4th - More downtime
February 5th - 29 minutes of downtime
Two class action law suits
Stock price dropped from US$62 to US$48 CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.18
Some statistics
One in four systems miscarry
20% turnover in staff is not uncommon
Major corporations have a backlog of up to a 30 months
Large systems take 3 to 5 years to develop
Corporations are spending up to 20% of revenue on Information Technology
Y2K problem took up to 50% of resources in at least one bank in Australia. Many of the systems were built in the 1980s CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.19
Product and Process
Both are key aspects in software engineering
We move from an emphasis on product to process, and back and forth
Structured programming - Product
Structured analysis and design - Process
Data encapsulation (OO languages) - Product
Capability Maturity Model/ISO9000 - Process
Next step?
We need to be able to deliver quality software products to our customers with a consistent, well-managed and cost-effective process
Product and process are not a dichotomy CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.20
The Software Product
Is not the same as a hardware product
Software is developed or engineered, it isn’t manufactured like a personal computer
Software doesn’t wear out
Most software is custom-built, rather than being assembled from existing components
A software product should
perform the required function
be reliable
be maintainable
be efficient
have an appropriate user interface
have an appropriate lifetime CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.21
A good software product?
CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.22
The Software Product
Is composed of
Programs
Data
Documentation
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requirements, analysis & design documents, walk through minutes, test plan, user manuals, etc.
often referred to as the “software configuration”
Two main types of product
Generic - eg. Windows, Macintosh application software
Bespoke - Systems created for specific application areas
Most software expenditure is generic
Most software development effort is bespoke CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.23
The Software Process
The set of activities and associated results which produce a software product
The sequence of steps required to develop and maintain software
Sets out the technical and management framework for applying methods, tools and people to the software task
Definition:
The Software Process is a description of the process which guides software engineers as they work by identifying their roles and tasks.
CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.24
Characteristics of a good process
Understandability
Visibility
Supportability
Acceptability
Reliability
Robustness
Maintainability
Rapidity CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.25
Two questions
Is there a right process for software engineers to adopt?
Will having a good process guarantee a good product?
CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.26
When do we need process?
We always have some process!
The larger the project, the greater the need for a formal process
Complexity of building a system when related to size is not linear.
Gigatron Gigatron 2 Deluxe Size 5,000 50,000 1 Effort Required 25 Errors after release 20 375 (15 times CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.27
Determining Process
Several Schemes
US Department of Defense use the Project Formality Worksheet [McC1997]
Projects rate between 12 (minimal formality) to 60 (maximum formality)
Most student projects are well under 20 and require very minimal formal process to be successful CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.28
Steps in a Generic Software Process
Project Definition
Requirements Analysis
Design
Program Implementation
Component Testing
Integration Testing
System Testing
System Delivery
Maintenance CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.29
Process Activities (1)
Project Definition
States the purpose of the project
Makes initial decision on political and technical feasibility of the project
Requirements Analysis
High level definition of the functionality of the system, primarily from the point of view of the users
Design
Looks at the software requirements of the system and the architecture of the system
Lower level design activities - data structures, interface representations, procedural (algorithmic) details CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.30
Process Activities (2)
Program Implementation
Writing or generating the code to build the system
Component Testing
Testing of the individual components while they are being built and after they have been completed
Integration Testing
Testing of the way individual components fit together
System Testing
Testing of the whole system usually in concert with the users (acceptance testing) CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.31
Process Activities (3)
System Delivery
Implementation of the system into the working environment and replacement of the existing system
Maintenance
Corrective
Adaptive
Perfective CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.32
References
[Pre200] Pressman, R., Software Engineering: A Practitioner's Approach, McGraw-Hill, 2000, (Chapters 1 and 2).
[McC1997] McConnell, S., Less is More: Jump-Start Productivity with Small Teams, Software Development, October 1997, pp. 28 34.
http://www.stevemcconnell.com/articles/art06.htm
CSE3308 - Software Engineering: Analysis and Design, 2004 Lecture 1A.33