SE Models Q & A #8. Question:Give a description of prototyping model. Answer: - This is a working system and the objective of the model is to develop those ideas which are tested regarding a new system and could be used again. ... Prototype model provide the design which gives the thoughts how system did the works.

1. Software Engineering II
By: Muhammad Usman
email:mu702823@gmail.com

2. Spiral Model
In 1988 Boehm developed the spiral model as
an iterative model which includes risk
analysis and risk management.
1. Build some software
2. See if it meets customer requirements
3. If no goto 1 else stop.

3. Each cycle follows a waterfall model by:
1. Determining objectives
2. Specifying constraints
3. Generating alternatives
4. Identifying risks
5. Resolving risks
6. Developing next-level product
7. Planning next cycle
Spiral Model

4. Spiral Model
Risk
Analysis
Verify
Rapid Prototype
Specification
Design
Implementation
Integration

5. Spiral Model

6. Advantages
1. Realism: the model accurately reflects the
iterative nature of software development on
projects with unclear requirements
2. Flexible: incoporates the advantages of the
waterfal and rapid prototyping methods
3. Comprehensive model decreases risk
4. Good project visibility.

7. Disadvantages
1. Needs technical expertise in risk analysis to
really work
2. Model is poorly understood by non-technical
management, hence not so widely used
3. Complicated model, needs competent
professional management. High
administrative overhead.

8. Agile Software Development
In agile software development, “agile” tends to
mean “the ability to respond to change.”

9. Change In Projects
 Changes From Requirements
 Customers Learn from the Solution
 Business Environment and Conditions Change
 Business Processes are Re-engineered
 Changes From Technology
 Tools/Platform Release New Versions
 Actual Tool/Platform Capabilities May Vary from Plans
 Changes From People
 Interactions are Complex
 Individual Behavior is Unpredictable

10. Agile Processes
 Extreme Programming
 Scrum
 Lean Development
 DSDM
 Crystal
 Adaptive Software Development
 Feature-Driven Development

11. XP Extreme Programming
 Programming in pairs
 Test driven development
 Continuous planning, change , delivery
 Continuous collaboration with customer
 No overtime!

12. XP Extreme Programming

13. Advantages
 Lightweight methods suit small-medium size
projects
 Produces good team cohesion
 Emphasises final product
 Iterative
 Test based approach to requirements and
quality assurance

14. Disadvantages
 Difficult to scale up to large projects where
documentation is essential
 Needs experience and skill if not to degenerate
into code-and-fix
 Programming pairs is costly
 Test case construction is a difficult and
specialised skill.

15. Synchronize-and-Stabilize
Model
 Microsoft’s life cycle model
 Requirements: Interview numerous potential
clients for the package and extract a list of
features of highest priority to the clients.
 Draw up specifications
 Divide the work into three or four builds.
 The 1st build: Most critical features.
 The 2nd build: The next most critical features.
 Each build is carried out by a number of small teams
working in parallel.

16. Synchronize-and-Stabilize
Model
 Synchronize at the end of each day:
Put the partially completed components
together and test and debug the resulting
product.
 Stabilize at the end of each build:
Fix remaining faults and no further changes will
be made to the specifications

17. Advantages:
The repeated synchronization step ensures that
the various components always work together.
The regular execution of the partially
constructed product makes the developers gain
early insight into the operation of the product
and modify the requirements if necessary during
the course of a build.