SDLC Prototype model: Software development life cycle prototype model is based on building software application prototypes. These application prototypes display the functional behavior of the product under development but in the actual procedure, it does not hold the exact logic of the original software product.
Design phases | Advantages | Disadvantages | Pros & Cons | Applications
The basic idea behind the working behavior of the prototype model is that in this SDLC model instead of freezing of customer requirements before a design or coding phase (likewise waterfall model) can proceed. A throwaway or a temporary prototype is built to understand the customer’s product requirements. This prototype model is developed under the current requirements of the product. By the use of these prototypes, the customer can get “a real behavior” of the developed product. In this model of SDLC the customer interactions with the prototype can enable the customer to better understand the requirements of the desired system. Customer involvement and providing valuable feedback about the functional behavior of the software product helps software developers and designers to better understand the problem and overcome the problem by continuously working. So that the exactly as per the user’s expectation product developed.
Prototyping SDLC modeling approach, also known as the evolutionary approach. This approach came into the picture after the failures of the final version of the software application development approach used in waterfall model. The failure in the waterfall model generally occurs when the changes in the requirement of the proposed system from the customer side or when a gap in between a better understanding of the customer requirement by the software development team. A gap in the first version of the developed application inevitably leads to the need for redoing the application. To overcome these limitations, the concept of prototyping was introduced.
Design of Prototype model:
The prototyping modeling approach is an attractive approach for complicated and large systems for which there is no manual process or existing system to help determine the requirements. The prototypes are usually improper systems and many of the details about the developed system are not built in the prototype. The ultimate goal of this model is to provide a system with overall functionality.
The following phases in the figure below represent the different phases of SDLC Prototype model:
- Requirement gathering and analysis:
In this phase of the prototype model, the basic requirement identification is done by the product analysis team members. It involves understanding the user functional requirement by the requirement analysis team. After completely understanding the user demand team members ready product requirement tools documents. But more intricate details of the internal design and external aspects like performance and security can be ignored at this stage.
- Quick Design:
In the quick design phase of the prototype model development team developed the initial prototype of the system. In this stage of the model, the very basic requirements are showcased and user interfaces are provided. These features used in quick design may not exactly work in the same manner as the actual software developed. But the overall working environment around is used to give the similar look and feel as the final product development to the customer in the prototype developed.
- Building prototypes:
This phase of the prototype model takes quick design from the output of the quick design and builds that system design locally. This local building prototype gives a look and feels similar as the final product that has to be designed.
- Customer evaluation:
After building the prototype of the system the customer review process is under work in the customer evaluation phase of the Prototype model. The customer checks the working functionality of the building prototype and gives feedback to the development team. This feedback from customers and stakeholders of the product is collected in an organized manner and used for further enhancements in the product under the development phase.
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- Refining product:
This phase is also called revising and enhancing the prototype. In the refining product, the development team discusses the customer feedback and reviews the building prototype, and if any issue occurred in the product then the team tries to refine the project and successively fulfill the customer’s desire for the system. In this stage, some negotiations happen with the customer based on different factors like time and budget constraints and the technical feasibility of actual implementation. These all changes accepted are again incorporated in the new Prototype developed and the cycle repeats until customer expectations are met.
- Engineer product:
After all successive feedback and positive reviews from the customer, the building prototype takes over by the software design and development team. The actual product is designed and developed in this phase of the prototype model.
These all phases get together give a successful environment to the SDLC prototype model.
Advantages and disadvantages of SDLC Prototype model:
Every software development model has its own advantages and disadvantages that decide the working area of the model. Here we are listing all the advantages and disadvantages of the prototype model:
Advantages of the SDLC Prototype model:
The advantage of developing software in the prototype model is that this model allows a high user interface of the customer with the developed system. The working methodology of the prototype model is to build a model which provides the actual look and feel of system being developed for customer review and feedback about the system functionality. Errors and issues can be detected very easily.
Disadvantages of the SDLC Prototype model:
To concern, the disadvantage of system development in the prototype model is increases the complexity of the system as the functional scope of the system is extended beyond the pre-scheduled function of the system. An incomplete application may cause the application not to be used as the full system and the functionality of the product.
Pros and Cons of Prototype model:
The SDLC prototype model is used in typical cases when the big amount of data and high functional system development. The decision should be taken very carefully in prototype modeling so that the efforts spent in building the prototype add considerable value to the final software developed. The model has its own pros and cons listed in the below table.
| Pros of prototype model | Cons of prototype model |
| High involvement of the customer before actual implementation of the product. | Risk of insufficient requirement analysis owing to too much dependency on prototype. |
| User gets a better understanding with the developed system when a working model of the system displayed in build prototype phase. | Users may get confused in the prototypes and actual systems. |
| Reduces time and cost as the defects can be detected much earlier. | Practically, this methodology may increase the complexity of the system as scope of the system may expand beyond original plans. |
| Quicker user feedback is available leading to better solutions. | Developers may try to reuse the existing prototypes to build the actual system, even when it’s not technically feasible. |
| Missing functionality can be identified easily. | The effort invested in building prototypes may be too much if not monitored properly. |
| Confusing or difficult functions can be identified. |
Application of SDLC Prototype Model:
The software development Prototype model is the most very useful approach in application software development. This model has a high level of user interactions with almost all phases of the model such as online systems. In the prototype model, the system development which needs users to fill out forms or go through various screens before data is processed can use prototyping very effectively to give the images similar to the actual working feel and look even before the actual software is developed.
One of the highly required applications of the system developed under the prototype model is to handle a high data processing environment. This model involves too much of data processing and most of the functionality is internal with a very little user interface that does not usually benefit from prototyping. The system developed under the prototype model could be an extra overhead in such projects and may need a lot of extra effort.
In the prototype model development team ensures that the end users constantly work with the system and review the system and provide feedback which is incorporated into the prototype to result in a usable system. They are excellent for designing good human-computer interface systems.
