Software Engineering

1
Software Engineering

• Peter Blanchfield

2
Course Content

• Software Engineering Concepts
• Software Engineering Tools
• Examples
• Object Orientation
• UML
• Agile modelling
• eXtreme programming
• IDE
• Rational Unified Process
• Group Project worth half the marks

3
Concepts Review?

• Why software Engineering?
• What is a good system?
• What is wrong with current systems?
• In general how can we better design software?

4
Tools to do what?

• Design lifecycle implies design
• Analysis of the current problem
• Methods of analysis
• Determining a solution
• Working out how to implement it
• How to test it
• Document it
• Keep it up to date

5
Object Orientation

• Allows
• Many of the concepts needed for well engineered
  software
• Is not the only way and
• Will not in itself save you
• But is a major tool

6
UML

• Will allow us to model many of our systems
• Can model most of the design steps
• Can be used to generate initial code
• Is not itself the answer

7
IDE

• Integrated Development Environment
• Example Microsoft Visual Studio
• C
• Combined with in house engines and libraries

8
Extreme Programming

• A design methodology
• Will make use of other tools
• Like IDE
• Maybe some UML
• Is not the answer

9
Rational Unified Process

• RUP
• A development methodology
• Offered itself as the answer but it is not

10
Agile modelling

• An alternative design concept
• Is still a tool
• Answers some problems better than the RUP
• But is not the answer

11
Assessment

• Exam worth 50
• Group work assignment worth 50

12
Books

• Any number of texts in the Library
• Pressman Software Engineering A Practitioners
  Approach
• Somerville Software Engineering
• Stevens (with) Pooley Using UML Software
  Engineering with Objects and Components
• http//amazon.co.uk/s/refnb_ss_b?urlsearch-alias
  3Dstripbooksfield-keywordsXNAGo.x8Go.y7

13
Group work assignment

• An opportunity to use design tools and IDE!
• To experience work in groups
• One project
• Many solutions!
• Assessed on how the group works
• As well as individual effort

14
Why?

• Major projects fail
• Because of lack of design
• Because of lack of communication
• Because people have to work together
• Because the customer seldom understands us
• Because we fail to understand the customer!
• You may be great as an individual
• But if you cannot work in a team you are no use
  as a software engineer

15
Robert L. Glass 1980s

• Describes the design process as
• understanding the problem
• decomposing the problem into goals and objects
• selecting and composing plans to solve the
  problem
• implementing the plans
• reflecting on the product and the process
• http//www.developerdotstar.com/mag/articles/glass
  _cognitive_view.html
• Which as he says is no more than a rewording of
  the common software development lifecycle
• Describes a piece of work to try and determine a
  good methodology

16
Start with

• A good designer and record how they work
• While trying not to interfere with that
• Failure is an essential part of successful
  design - ibid
• Good designers build on experience
• Have a go, fail, redesign, fail again, redesign,
  succeed!
• Next time they reuse
• A RARE example

17
Teams

• The design process needs to fit into teams
• Need to have formal methods
• Some important issues
• Conflict
• Communication
• Responsibility

18
Teams Conflict

• Inevitable
• but does not need to be destructive
• Work on conflicts resolve them

19
Teams - communication

• Using standard tools comes into play
• Make sure you all mean the same thing!
• House Style!
• In House Engines
• Including the customers
• Rapid and agile development methodologies would
  insist we include the customer in the feedback
• That we feedback frequently

20
Teams - responsibility

• When working alone
• You are responsible for everything
• When working in a team
• Things get missed
• Not my responsibility

21
Software development

• 1980s crisis
• Many proposed solutions
• Still problems today
• Many caused by
• Teams
• But projects are too big
• Design practices
• Promote communication
• Medium size projects better with
• Agility, eXtreme methods

22
Waterfalls are not the only method that does not
work

• Even the person who proposed the waterfall method
  expected the process to be iterative
• Many methods
• Many solutions
• None work or fail
• It is the people who do both
• Need
• Agile minds
• Experience
• Humility
• Good communication