Protoytyping Model
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The document describes the prototype model, which involves quickly building prototypes early in the development process to gather user feedback and test aspects of the design. It defines prototyping and discusses developing prototypes through iterative cycles of building, reviewing with customers, revising based on feedback, and retesting until requirements are met. The document also outlines types of prototyping like throwaway, evolutionary, and operational, as well as advantages like reducing costs and risks, and disadvantages like potential scope creep.
Protoytyping Model
- 1. Prototype Model Presented TO:- Resp. Inam-ul-Haq Presented By:- Sohaib Saleem Ch. Roll# 3008 17 April 2015 1University Of Education, Okara Campus.
- 2. Tables Of Contents • Prototyping Model • Scenario • Developing A Prototype: • Prototyping Process • Prototyping Model- Phases • How To Build Prototype? • Where Use? • Steps In Prototyping Model:- • Strength And Weakness Of Prototyping • Advantages And Disadvantages Of Prototype Model • Types Of Prototyping • When To Use Prototype Model? • Summery • References 17 April 2015 2University Of Education, Okara Campus.
- 3. What Is Prototyping Model? Prototyping Model is the process of quickly putting together a working model (a prototype) in order to test various aspects of a design, illustrate ideas or features and gather early user feedback. Wikipedia IEEE defines prototyping as “ A type of development in which emphasis is placed on developing prototypes early in the development process to permit early feedback and analysis in support of the development process.” The prototyping model requires that before carrying out the development of the actual software , a working prototype of the system should be built. 17 April 2015 3University Of Education, Okara Campus.
- 4. Prototype •A Prototype is an early sample or model built to test a concept or process or to act as a thing to be replicated or learned from. •. A prototype is a model or a program which is not based on strict planning, but is an early approximation of the final product or software system 17 April 2015 4University Of Education, Okara Campus.
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- 6. Scenario •Complete Set of requirement are not available. •Start development with initial set of requirements. •Feel of the product with initial requirements expected. •Few more new requirements will be added later. 17 April 2015 6University Of Education, Okara Campus.
- 7. Developing a Prototype: • Outline of the prototyping process 1. Identify basic requirements Determine basic requirements including the input and output information desired. Details, such as security, can typically be ignored. 2. Develop Initial Prototype The initial prototype is developed that includes only user interfaces. 3. Review The customers, including end-users, examine the prototype and provide feedback on additions or changes. 4. Revise and Enhance the Prototype Using the feedback both the specifications and the prototype can be improved. Negotiation about what is within the scope of the contract/product may be necessary. Note: If changes are introduced then a repeat of steps #3 and #4 may be needed. 17 April 2015 7University Of Education, Okara Campus.
- 8. . • . Design Implement Test Maintain Requirements gathering Quick design Build prototype Refine requirements incorporating Customer suggestion Customer evaluation Of prototype Acceptance By customer Prototype development Iterative development 17 April 2015 8University Of Education, Okara Campus.
- 9. Evolutionary models of Prototyping 17 April 2015 9University Of Education, Okara Campus.
- 10. Prototyping Model- Phases •Communication:- • Define the overall Objectives. • Identifies the initial set of Requirements. • Quick Plan:- • Quick Plan of Iteration is Done. • Modeling and Quick Design:- • Build the Model base on requirements. • Design Development is done Quick. • Construction of prototype:- • Prototype is constructed based on the of design. • Deployment, Delivery and feedback:- • Prototype is evaluated by the customer. • Feedback is taken to refine the requirements for next iteration. 17 April 2015 10University Of Education, Okara Campus.
- 11. How to Build Prototype? • Build a prototype of the basic functionality, especially the interface • Test the prototype, which will uncover design errors • Correct the errors • Repeat until you have a clean design • Prototyping is • a major tool for improving usability • Heavily used in industry 17 April 2015 11University Of Education, Okara Campus.
- 12. Where Use? •Developers build a prototype during the requirements phase. •Prototype is evaluated by end user. •User give corrective feedback. •Developers further refine the prototype. •When the user is satisfied, the prototype code is brought up to the standards need for a final product. 17 April 2015 12University Of Education, Okara Campus.
- 13. Steps In Prototyping Model:- • A preliminary project plan is developed. • A partial high level paper model is created. • The model is source for a partial requirements specification. • A prototype is built with basic and critical attributes. • The design builds:- The database User interface Algorithm function • The designer demonstrative the prototype the user evaluate for problems and suggests improvements 17 April 2015 13University Of Education, Okara Campus.
- 14. Strength Of Prototyping • Customer can “see’’ the system requirements. • Developer learn from customer. • A more accurate end product. • Unexpected requirements accommodated. • Allows for flexible design and development. • Steady, visible sign of progress produced. • Interaction with the prototype stimulates awareness of additional needed functionality. • Misunderstandings between software users and developers are exposed • Missing services may be detected and confusing services may be identified 17 April 2015 14University Of Education, Okara Campus.
- 15. Weakness Of Prototyping Model:- •Tendency to abandon structured program development for “code-and-fix” development. •Bad reputation for “quick-and-dirty” methods. •Overall maintainability may be overlooked. •The customer may want the prototype delivered. •Process may continue forever (scope creep). 17 April 2015 15University Of Education, Okara Campus.
- 16. Advantages of Prototype model 1. Reduces development time. 2. Reduces development costs. 3. Requires user involvement. 4. Missing functionality can be identified easily 5. Encourages innovation and flexible designs 6. Results in higher user satisfaction 7. Part of the product is visible at early stage. 8. Scope for accommodating new requirements. 17 April 2015 16University Of Education, Okara Campus.
- 17. Disadvantages of Prototype model • Extending the prototype indefinitely also creates problems. • Developer misunderstanding of user objectives. • Expense of implementing prototyping. • Excessive development time of the prototype. • Insufficient analysis. • User confusion of prototype and finished system. • Expensive • Time Consuming. 17 April 2015 17University Of Education, Okara Campus.
- 18. When To Use Prototype Model? •Requirements •are unstable or have to be clarified. •As the requirements clarification stage of waterfall model. •Develop user interface. •Short-lived demonstrations. •New, original development. •With the analysis and design portion of Object- Oriented development 17 April 2015 18University Of Education, Okara Campus.
- 19. Users’ Role In Prototyping • Experimenting with the prototype. • Giving open reactions to the prototype. • Suggesting additions to and/or deletions from the prototype. 17 April 2015 19University Of Education, Okara Campus.
- 20. Types of Prototyping •Throw away prototyping •Evolutionary prototyping •Operational prototyping 17 April 2015 20University Of Education, Okara Campus.
- 21. Throw Away Prototyping :- • Objective - Derive end system requirements • Throw away prototyping is one type of approach where an initial prototype is built mainly focusing on the poorly understood requirements • Once the requirements are understood requirements document is updated and a conventional development process is followed to build system 17 April 2015 21University Of Education, Okara Campus.
- 22. Evolutionary Prototyping • Objective – Deliver a working system + requirements • Evolutionary prototyping is the one in which a system is build using the well understood requirements. 17 April 2015 22University Of Education, Okara Campus.
- 23. Operational Prototyping • Used when requirements are either critical and understood or not critical and poorly understood . • Throw away prototypes are selectively built on top of evolutionary prototype • A trained prototyper keeps track of user . 17 April 2015 23University Of Education, Okara Campus.
- 24. Summery • Prototype model is useful when either the customer or developer is not sure about the exact requirements. • Developer creates the model of the system to build called as prototype. • Advantages includes scope for accommodating new requirements and less technical risks. • At times, prototyping is time consuming and expensive but it is extremely useful for doing proof of concepts. 17 April 2015 24University Of Education, Okara Campus.
- 25. References:- • Summerville, I. (2000). Software Engineering. Pearson publications. • Paper Prototyping: the fast and easy way to design and refine user interfaces • http://paperprototyping.com/ • http://hci.epfl.ch/teaching/hci/course_material/lofi-prototype/lecture5- lofi_proto-x6.pdf • http://istqbexamcertification.com/what-is-prototype-model-advantages- disadvantages-and-when-to-use-it/ • http://www.slideshare.net/sadhana8/prototype-model • http://www.tutorialspoint.com/sdlc/sdlc_software_prototyping.htm • Sohaib Saleem. 17 April 2015 25University Of Education, Okara Campus.