prototyping - introduction

An Introduction to Software Prototyping

Prepared by:Shakir Mushtaq – Quality AssuranceOvex Technologies

What is a PrototypeThe word “Prototype” derives from two

Greek words:

(protos) means "first" and

(typos) means "impression” or “Model”

Primitive Form

What is a PrototypeA Series of Screen sketches

A PowerPoint presentationA storyboard i.e. cartoon like series of scenesA mockup of a process or functionalityA video simulating the use of a systemPiece of software with limited or no functionality

A mechanism for gaining better understanding of the customer’s needs

Normally a non functional design of a product

Early sample or model built to test a concept / process

Typically done very early in the design process

Can be used throughout the SDLC

What is Software Prototyping

Purpose of Software Prototyping

The software designer can get valuable feedback from the users early in the project

You can’t test until you implement so Prototyping sometimes becomes necessity

Helps the developer and the customer to find out and understand the requirements

To assess the set of requirements that makes a product successful in the market

Prototyping can also avoid the great expense and difficulty of changing a finished software product

Delivers “Look and Feel” of the interface

Process Model of the Prototyping Approach

Dimensions of prototypes

Horizontal prototypeDisplays “breadth” of functionality

Vertical prototypeFull functionality and performance of a “slice” or small part of the system

Horizontal prototype

Vertical prototype

(Broad but only on top-level)

(Deep, but some or only one function)

Types of prototypingThrowaway prototyping:

Constructed with the idea that it will be discarded and the final system will be built from scratch

After gathering preliminary requirements, a simple working model of the system is constructed to visually show the users what their requirements may look like when they are implemented into a finished system.

Evolutionary prototyping:Acknowledges that we do not

understand all the requirements and builds only those that are well understood

Allows the development team to add features, or make changes that couldn't be conceived during the requirements and design phase

1st Level

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2nd Level

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3rd Level

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Advantages of PrototypingProvides better system to Users, as users

have natural tendency to change their mind in specifying requirements

The users get a better understanding of the system being developed

Errors can be detected much earlier

Changes cost more to implement as they are detected later in development

The early determination of what the user really wants can result in faster and less expensive software

Disadvantages of PrototypingUsing, or perhaps misusing, prototyping can also

have disadvantages:

Insufficient analysis

User confusion of prototype and finished system

Developer misunderstanding of user objectives

Developer attachment to prototype

Excessive development time of the prototype

Expense of implementing prototyping

Summary

What is a prototype

What is Software prototyping

Purpose of Software Prototyping

Process Model of Software Prototyping

Dimensions of Software Prototyping

Types of Software Prototyping

Advantages and disadvantages of prototyping

Thank you for your

Time!!!