The Software
Prototyping refers to building software application prototypes which display
the functionality of the product under development but may not actually hold
the exact logic of the original software.
Software prototyping
is becoming very popular as a software development model, as it enables to
understand customer requirements at an early stage of development. It helps get
valuable feedback from the customer and helps software designers and developers
understand about what exactly is expected from the product under development.
What is Software Prototyping?
- Prototype is
a working model of software with some limited functionality.
- The
prototype does not always hold the exact logic used in the actual software
application and is an extra effort to be considered under effort
estimation.
- Prototyping
is used to allow the users evaluate developer proposals and try them out
before implementation.
- It also
helps understand the requirements which are user specific and may not have
been considered by the developer during product design.
Following is the
stepwise approach to design a software prototype:
- Basic
Requirement Identification: This step involves understanding the
very basics product requirements especially in terms of user interface.
The more intricate details of the internal design and external aspects
like performance and security can be ignored at this stage.
- Developing
the initial Prototype:
The initial Prototype is developed in this stage, where the very basic requirements
are showcased and user interfaces are provided. These features may not
exactly work in the same manner internally in the actual software
developed and the workarounds are used to give the same look and feel to
the customer in the prototype developed.
- Review of
the Prototype:The
prototype developed is then presented to the customer and the other
important stakeholders in the project. The feedback is collected in an
organized manner and used for further enhancements in the product under
development.
- Revise and
enhance the Prototype:
The feedback and the review comments are discussed during this stage and
some negotiations happen with the customer based on factors like , time
and budget constraints and technical feasibility of actual implementation.
The changes accepted are again incorporated in the new Prototype developed
and the cycle repeats until customer expectations are met.
Prototypes can
have horizontal or vertical dimensions. Horizontal prototype displays the user
interface for the product and gives a broader view of the entire system,
without concentrating on internal functions. A vertical prototype on the other
side is a detailed elaboration of a specific function or a sub system in the
product.
The purpose of
both horizontal and vertical prototype is different. Horizontal prototypes are
used to get more information on the user interface level and the business
requirements. It can even be presented in the sales demos to get business in
the market. Vertical prototypes are technical in nature and are used to get
details of the exact functioning of the sub systems. For example, database
requirements, interaction and data processing loads in a given sub system.
Software Prototyping Types
There are
different types of software prototypes used in the industry. Following are the
major software prototyping types used widely:
- Throwaway/Rapid
Prototyping:
Throwaway prototyping is also called as rapid or close ended prototyping.
This type of prototyping uses very little efforts with minimum requirement
analysis to build a prototype. Once the actual requirements are
understood, the prototype is discarded and the actual system is developed
with a much clear understanding of user requirements.
- Evolutionary
Prototyping:
Evolutionary prototyping also called as breadboard prototyping is based on
building actual functional prototypes with minimal functionality in the
beginning. The prototype developed forms the heart of the future
prototypes on top of which the entire system is built. Using evolutionary
prototyping only well understood requirements are included in the
prototype and the requirements are added as and when they are understood.
- Incremental
Prototyping:
Incremental prototyping refers to building multiple functional prototypes
of the various sub systems and then integrating all the available
prototypes to form a complete system.
- Extreme
Prototyping : Extreme
prototyping is used in the web development domain. It consists of three
sequential phases. First, a basic prototype with all the existing pages is
presented in the html format. Then the data processing is simulated using
a prototype services layer. Finally the services are implemented and
integrated to the final prototype. This process is called Extreme
Prototyping used to draw attention to the second phase of the process,
where a fully functional UI is developed with very little regard to the
actual services.
Software Prototyping Application
Software Prototyping
is most useful in development of systems having high level of user interactions
such as online systems. Systems which need users to fill out forms or go
through various screens before data is processed can use prototyping very
effectively to give the exact look and feel even before the actual software is
developed.
Software that
involves too much of data processing and most of the functionality is internal
with very little user interface does not usually benefit from prototyping.
Prototype development could be an extra overhead in such projects and may need
lot of extra efforts.
Software Prototyping Pros and Cons
Software
prototyping is used in typical cases and the decision should be taken very
carefully 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
discussed as below.
Following table
lists out the pros and cons of Big Bang Model:
Pros
|
Cons
|
- Increased
user involvement in the product even before implementation
- Since a
working model of the system is displayed, the users get a better
understanding of the system being developed.
- Reduces
time and cost as the defects can be detected much earlier.
- Quicker
user feedback is available leading to better solutions.
- Missing
functionality can be identified easily
- Confusing
or difficult functions can be identified
|
- Risk of
insufficient requirement analysis owing to too much dependency on
prototype
- Users may
get confused in the prototypes and actual systems.
- Practically,
this methodology may increase the complexity of the system as scope of
the system may expand beyond original plans.
- Developers
may try to reuse the existing prototypes to build the actual system,
even when its not technically feasible
- The effort
invested in building prototypes may be too much if not monitored
properly
|
