Software Development Models

The "Waterfall" and "Whirlpool" software development models are two different types of system Development or Lifecycle Models which are created to maintain repeatable and predictable process methodologies. These Lifecycle models came into being when companies were making the transition from manual procedures to automated procedures and they were introduced to make this process easier by bringing in a structured approach to building or improving systems.

The Waterfall Software Development Model

 This is the most traditional software model which has a linear structure to it.

 'The Design starts after the requirements analysis is done. And coding begins after the design is done. Once the programming is completed, the code is integrated and testing is done. On successful completion of testing, the system is installed. After this the regular operation and maintenance of the system takes place'. 

  

The Waterfall Software Lifecycle Model

With the Waterfall structure, each stage of development is completed before the next stage begins and therefore the output from one stage is the input of the next stage and so therefore cannot be changed or modified without affecting the rest of the production, which is a consequence of using this particular lifecycle model. Although this method has many advantages; it is easy to explain and follow, it is well defined and ensures early detection of errors it also has its limitations for the fast moving rate of technology today. This method needs the requirements to be decided before the rest of the development can be started which is not always the way production goes as some may like to start designing the system and go back to tweak bits to suit requirement.

The Whirlpool Software Development Model

The whirlpool method was designed for projects where requirements are more volatile.

Risk assessment and prioritising are used in this method to flag up any problems before they become too expensive ot theatening. Developers can start one stage of the design process before going to and improving the planning process. 'An important feature of the model is that each cycle of the spiral is completed by a review, which covers all the products developed during that cycle, including the plans for the next cycle. The spiral model works for developed as well as enhancement projects'.

 

Using the Whirlpool Software Development Model in Web Page Design

 

As the Whirlpool design method allows you to tackle various stages of the design process at the same time it would be better suited to use in the designing of Web pages than the Waterfall method. This is because coding is constantly being changed in the production of a web page to improve the overall product and making a change in the Waterfall method would have a knock on effect to the rest of th production whereas with the Whirlpool method there is tolerance for going back and making changes. Also the requirments cannot be frozen in this method as they can be in the Waterfall method which often leads to out of date outcomes in the final product. As the Whirlpool method allows the developer to go "up the waterfall" various stages of the design can regularly be updated or improved allowing an up to date product overall whick is important with the rate that technology and user trends within the field of Web design are moving.

References:

FreeTutes.com. The Tutorial Website. [online] Waterfall Software Development Lifecycle Model. Available at: http://www.freetutes.com/systemanalysis/sa2-waterfall-software-life-cycle.html Accessed on: 12th January 2010.

FreeTutes.com. The Tutorial Website. [online] The Spiral Lifecycle Model. Available at: http://www.freetutes.com/systemanalysis/sa2-spiral-model.html Accessed on: 12th January 2010

Tecademy [online] The Development Lifecycle. Available at: http://www.puffinonline.com/Tecademy/003%20Waterfall%20vs%20Whirlpool.pdf Accessed on: 12th January 2010