Prototype Models in Software Engineering

Software engineering and development is a diverse and wide-spanning field covering various levels in IT development. For many, a Prototype Model is still a paradox yet in essence they are different sample software methods in web development with pros and cons (advantages and disadvantages). In fact, prototypes have proven useful and valuable when clients don�t have a clear idea of the types or kinds of features and functions they want in their software product.

So in detail, what is the value, purpose and function of having prototypes? And what are the different types of prototypes available in software engineering today? Are there any specific advantages and disadvantages of prototyping? Let us examine each of these below in detail.

What is the Purpose and Function of Prototyping?

Prototyping function or purpose is when requirements of the final product aren�t clearly stated or known it becomes a guiding roadmap. It is adapted when requirements are rapidly changing. Prototyping can be used in developing user interfaces, high technology software-intensive systems, and systems with complex algorithms and interfaces. It�s valuable in showcasing the technical feasibility of software products.

Different Types of Prototype Models

Software product developers have the option of choosing prototype models primarily going by the final software product requirements given by the client. These are some of the common prototyping methods and approaches.

1. Rapid Throwaway Prototyping

This prototyping approach develops prototypes rapidly based on the initial requirements and then the client reviews and gives feedback. When the client gives feedback, the final requirements are added to the final product before starting development. The previously developed prototype is thrown away as it is useless in the final product. This prototyping approach is also known as close-ended prototyping.

2. Evolutionary Prototyping

In evolutionary prototyping, a prototype is made, and the client gives feedback on the same. Going by the feedback, the prototype is refined till the client agrees to a final product. This approach saves time when compared to rapid throwaway prototyping. Also, the previous prototype is reworked as opposed to starting afresh by developing a new prototype from start. Evolutionary prototyping is also known as breadboard prototyping.

3. Incremental Model

This model is divided into smaller prototypes. The prototypes are then developed separately. Function and features are added to each prototype till the final product is done. These prototypes are joined to create one final product. The method cuts the downtime it takes for the user to give feedback to the application development team. Although inconsistencies may come up in joining the sub prototypes together. That�s why extra professionalism is crucial when putting the separate sub prototypes together. It requires high-level skills to execute precise requirements and needs when the end product is placed together.

4. Extreme Prototyping

It is usually adopted for specific web applications and has three distinct phases in its processes.  These include among others:

(a). the first sub-phase is a basic prototype having static pages made with HTML pages.

(b). the second sub-phase is the simulation of data processing using the service layer.

(c). the third sub-phase is the implementation of services and activation of the final product prototype.

This method is primarily adapted for web development. It has three clear and distinct phases which are all sequence-independent phases with each leading to a new accomplishment. This approach makes the project cycle and delivery fast, keeps the entire Mobile Application Development team focused con product delivery as opposed to finding and meeting all needs and specifications.

Major Phases in the Prototype Models

1. Initial Consultation

The business analysts and development team are in charge of gathering the requirements and specifications discuss the needs of the product and consulting all possible stakeholders or clients. Developers research the various details that users may want in the software or system. Clients or users are asked in this process to know what they really want in their software/system. The feedback received is used to enhance the product under development.

2. Quick Plan

After consulting, discussing and deciding on the basic requirements, a quick plan of the initial prototype is made.

3. Modelling Quick Design

Based on the gathered details developers design a basic replica of the system after knowing all the requirements. It has basic vital features such as software input and output formats. Rather than the entire plan, it focuses on the aspects that are visible to the user. This includes the user interface (UI) design of the prototype.

4. Prototype Development

At this phase, the designed prototype is coded and developed. A basic prototype is developed showing the most basic requirements and user interface. This is a replica of what the user wants in the software product. However, there is a high possibility that most of the features and functions may change over time with client feedback and opinion and not be part of the final product. This prototype is sent for evaluation by clients and users. The feedback plays a vital role as it helps to know exactly the changes that need to be added to the final product.

5. Prototype Deployment, Delivery and Feedback

The initial prototype design is deployed and clients can access it for use. Clients can review and evaluate the prototype and give feedback to the consultation and development teams. The phases keep repeating till the final product deployment. The phase-only stops when a final prototype is built with all the user requirements. To make user requirement based prototypes, changes are inevitable based on the user feedback and opinion.

6. Final Product Design, Testing, Implementation and Maintenance

When clients accept a prototype, the final software product can be designed, developed and maintained by the web development team. The final product still goes through testing by the software testing team and when passed can go live. The final product is deployed and can be used by the clients and users. It is entirely based on the improved prototype with the users or clients requirements. Routine maintenance is performed on the system to minimize downtime and prevent large-scale failures. This is a more reliable and standard product that exemplifies all user requirements and is ready to go live.

Pros and Cons of Prototyping

There is always a positive and negative side to everything. Similarly, there are pros and cons to prototype models and the Various Phases of Prototyping. These can range from basic to advanced issues as it happens with all software development and engineering. These are the unique pros and cons of software engineering prototyping.

Pros of Prototyping

1. Drastically eliminates the risk or possibility of wrong user requirement
2. Clients can see the partial product early on in the product life cycle. It ensures higher customer satisfaction and comfort with the final product.
3. Prototype reuse by developers for future projects is a possibility, especially with matching criteria or requirements.
4. Complex functions and features can be identified and designed in a more user-friendly way.
5. Additional customer requirements are easily adaptable since there is room for product refinement and improvement.
6. Product success ratio is stronger as there is sustained user/client engagement
7. Fast error detection and correction as the system is made step by step with review and feedback from clients.
8. Architectural design flexibility is a plus for easy refinement.
9. Faster and reliable client feedback leads to better software solutions compatible with requirements and needs.
10. The client or user has a clear and better knowledge of the system under development. He develops an early grasp of all its operational intricacies.
11. Missing or malfunctioning functions and features can be easily seen and added or rectified.

Cons of Prototyping

1. It requires 100% assured customer commitment in project development.
2. Impossible to complete the project if clients completely withdraw from the project.
3. It requires extensive customer consultation and collaboration
4. Results in a higher cost to customers with the prolonged development cycle
5. Professional tools and techniques are required to build a prototype model. That means expertise is a necessity at every level for proper prototyping.
6. Some software products are too client-specific or centric and therefore not for the general market. Limited scope for replication.
7. Cost of the prototyping tools is excessively high.
8. Impossible to calculate and tell project duration and ultimate cost both financially and human resource-wise.
9. And it is a time-consuming process as perfection always demands.
10. There is always a possibility of falling back into the code and fixing minus clear requirement analysis, design, customer evaluation, and feedback.

Sometimes it is very hard to add all the changes demanded by the client.

There may occur wide variation in requirements all the time prototype is evaluated and feedback given by the client.

Poor documentation as there are several changes due to the shifting client requirements.

In the coding process, since developers don�t possess a broad perspective of what�s next, they may adopt underlying architecture unsuitable for the final product.

Summary

In the end, prototyping is all about ensuring the creation of a reliable product without room for error and satisfying the client needs. Similarly, Prototype Models are functional sample products of what is yet to come. They are not only helpful and vital in developing user interfaces but also are indispensable in high technology software and systems with complex algorithms and interfaces. Prototyping will always provide the best workable solution based on precise client needs and requirements. 

The prototyping process creates functional replicas of any product or system still to be built. That means a direct insight into what the final product looks like with all its features and functions. Prototyping is also very valuable for gaining customer feedback and opinion on the product design, features and overall performance.