Topic Name: Selection of an appropriate project approach

Project Approach

• An approach is a method used to run the project from inception to completion.
• Often called Methodology.
• Need to used project methodology:-
• To determine how the project going to run.
• To define the properties of the product.

Selection of project approaches

Process Domains:-

→Consumer

→Business , Industrial

→Real time

→Scientific

Classes of Product System:-

→New product ,Re-Engineering of existing product.

→ Component integration .

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Selection of project approaches

Software Development Life cycle:-

→Agile programming: Extreme programming(XP), Dynamic System Developing Method(DSDM),

Rapid Application Development(RAD).

→Waterfall and V-process Model.

→Prototype , Spiral and Incremental Deliveries.

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Steps of Project Analysis

• Identify project as either objective driven or product driven.
• Analyze other project characteristics by asking:–

→ Will we implement a data-oriented or a process oriented system?

→ Will the software to be produced be a general tool or application specific?

Steps of Project Analysis

→Are there specific tools available for implementing the particular type of application?

e.g.:- does it involve concurrent processing?

Is the system knowledge-based?

Will the system to be produced makes heavy use of computer graphics?

Steps of Project Analysis

• Is the system to be created safety critical?
• Is the system designed to carry out predefined services or to be engaging and entertaining?
• What is the nature of the hardware/software environment in which the system will operate?

Steps of Project Analysis

• Identify high-level project risks.
• The more uncertainty in the project the more the risk that the project will be unsuccessful.
• Recognizing the area of uncertainty allows taking steps towards reducing its uncertainty.
• Uncertainty can be associated with the products, processes, or resources of a project.

Steps of Project Analysis

Product uncertainty:

→How well are the requirements understood.

→The users themselves could be uncertain about what the system is to do.

Process uncertainty:

• For the project under consideration, the organization will use an approach or an application building-tool that it never used before.

Steps of Project Analysis

Resource uncertainty:-

→The main area of resource uncertainty is the availability of the staff with the right ability and experience.

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General approach

→Look at risks and uncertainties e.g.

• are requirement well understood?
• are technologies to be used well understood?

→Look at the type of application being built e.g. information system? embedded system?

• criticality? differences between target and development environments?

→Clients’ own requirements

• need to use a particular method

Structure versus speed of delivery

• Structured approach
• Also called ‘heavyweight’ approaches
• Step-by-step methods where each step and intermediate product is carefully defined
• Emphasis on getting quality right first time
• Example: use of UML (Unified Modeling Language )
• Future vision: Model-Driven Architecture (MDA). UML supplemented with Object Constraint Language, press the button and application code generated from the UML/OCL model

Structure versus speed of delivery

• Agile methods
• Emphasis on speed of delivery rather than documentation.
• RAD Rapid application development emphasized use of quickly developed prototypes.
• JAD Joint application development. Requirements are identified and agreed in intensive workshops with users .

Software Process Models

• Waterfall Model.
• V-process Model.
• Spiral Model.
• Software prototyping.
• Phased Development Model.
• incremental development model.
• iterative development model.

The waterfall Model

• The waterfall model
• Plan-driven model. Activities are planned in advance and progress is measured against plan

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Waterfall Model

• This model is only appropriate when the requirements are well-understood and changes will be fairly limited during the design process.
• Few business systems have stable requirements.
• The waterfall model is mostly used for large systems engineering projects where a system is developed at several sites.

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Incremental Model

Spiral Model

• The Spiral Development ( or Lifecycle) Model is a systems development method used in information technology.
• It combines the features of the prototyping model and the waterfall model.
• It is favored for large, expensive, and complicated models.

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