10.36.1 Purpose
Prototyping is used to elicit and validate stakeholder needs through an iterative process that creates a model or design of requirements. It is also used to optimize user experience, to evaluate design options, and as a basis for development of the final business solution.
10.36.2 Description
Prototyping is a proven method for product design. It works by providing an early model of the final result, known as a prototype. Prototyping is used to identify both missing or improperly specified requirements and unsubstantiated assumptions by demonstrating what the product looks like and how it acts in the early stages of design.
Prototypes can be non-working models, working representations, or digital depictions of a solution or a proposed product. They can be used to mock up websites, serve as a partially working construct of the product, or describe processes through a series of diagrams (such as workflow). Business rules and data prototypes can be used to discover desired process flow and business rules.
Data prototyping can be used for data cleansing and transformation.
10.36.3 Elements
.1 Prototyping Approach
There are two common approaches to prototyping:
- Throw-away: prototypes are generated with simple tools (such as paper and pencil, a whiteboard, or software) to serve the goal of uncovering and clarifying requirements. The prototype may be updated or evolve during the course of discussion and development, but does not become workable code or get maintained as a deliverable once the final system or process is implemented. This method is helpful for identifying functionality or processes that are not easily elicited by other techniques, have conflicting points of view, or are difficult to understand. These prototypes can be an inexpensive tool to uncover or confirm requirements that go beyond an interface including requirements related to processes, data, and business rules.
- Evolutionary or Functional: prototypes are created to extend initial requirements into a functioning solution as requirements are further defined through stakeholder use. This approach produces a working solution and usually requires a specialized prototyping tool or language. These prototypes may be used in the final solution. If specialized software is used, business processes, rules, and data can be simulated to evaluate the impact of changes and validate desired outcomes.
.2 Prototyping Examples
There are many forms of prototyping in use today.
Each of the following can be considered a form of prototyping:
- Proof of Principle or Proof of Concept: is a model created to validate the design of a system without modelling the appearance, materials used in the creation of work, or processes/workflows ultimately used by the stakeholders.
- Form Study Prototype: is used to explore the basic size, look, and feel of a product that will be manufactured, without creating actual functionality. It is used to assess ergonomic and visual factors using a sculptural representation of the product made from inexpensive materials. This type of prototype may also be used to model a workflow or navigation at a high level in order to identify gaps or inconsistencies in the possible solution of the properties (for example, appearance, configuration).
- Usability Prototype: is a product model created to test how the end user interacts with the system without including any of the properties (for example, appearance, configuration).
- Visual Prototype: is a product model created to test the visual aspects of the solution without modelling the complete functionality.
- Functional Prototype: is a model created to test software functionality, qualities of the system for the user (for example, appearance), and workflow. It is also referred to as a working model and is used both to simulate business processes and business rules and to evaluate software function calls.
.3 Prototyping Methods
The following is a list of commonly used methods for prototyping:
- Storyboarding: is used to visually and textually detail the sequence of activities by summing up different user interactions with the solution or enterprise.
- Paper Prototyping: uses paper and pencil to draft an interface or process.
- Workflow Modelling: depicts a sequence of operations that are performed and usually focuses solely on the human aspect.
- Simulation: is used to demonstrate solutions or components of a solution. It may test various processes, scenarios, business rules, data, and inputs.
10.36.4 Usage Considerations
.1 Strengths
- Provides a visual representation for the future state.
- Allows for stakeholders to provide input and feedback early in the design process.
- When using throw-away or paper prototyping methods, users may feel more comfortable being critical of the mock-up because it is not polished and release-ready.
- A narrow yet deep vertical prototype can be used for technical feasibility studies, proof of concept efforts, or to uncover technology and process gaps.
.2 Limitations
- If the system or process is highly complex, the prototyping process may become bogged down with discussion of “how” rather than “what”, which can make the process take considerable time, effort, and facilitation skill.
- Underlying technology may need to be understood or assumed in order to initiate prototyping.
- If the prototype is deeply elaborate and detailed, stakeholders may develop unrealistic expectations for the final solution. These can range from assumed completion dates to higher expectations of performance, reliability, and usability.
- Stakeholders may focus on the design specifications of the solution rather than the requirements that any solution must address. This can, in turn, constrain the solution design. Developers may believe that they must provide a user interface that precisely matches the prototype, even if more elegant technology
and interface approaches exist.
