Usability in the Product Development Life Cycle

When Usability Evaluations Should Be Done in the Product Development Life Cycle

From a user-centered perspective, usability evaluations should start early in the development process and occur repeatedly throughout the design cycle, not just when the product is completed.

Usability testing methods can be adapted for any of the general phases detailed below in the software or technology product development process. Usability evaluation at each phase is a critical part of ensuring that the product will actually be used and be effective for its intended purpose(s).

Where Usability Evaluation Fits into the Product Development Life Cycle

Phase 1 - Concept Exploration

Phase 1 Processes:

• Ideas for the software/technology product to help users solve problems or accomplish goals are developed.
• What the product needs to do (requirements analysis) and how the product will be used (task analysis) are explored.
• Platform capabilities and constraints are considered.
• The Usability focus is on getting the product to work.

Usability evaluations in Phase 1 can yield information about:

• the need for the product
• the needs for particular functions/features of the product.

Key Usability Tests in Phase 1: User Needs Assessments, Laboratory User Testing of paper mock-ups or prototypes

Phase 2 - Demonstration and Validation

Phase 2 Processes:

• The concept is implemented.
• Product requirements and constraints are refined and prioritized in order to identify or select those elements critical to the prototype.
• The key market is defined.
• The Usability focus is on having the right functions.

Usability evaluations in Phase 2 can yield evidence of the success or failure of the design concept.

Key Usability Tests in Phase 2: Heuristics and Walkthrough evaluations and Laboratory User Testing

Phase 3 - Detailed Design and Construction

Phase 3 Processes:

• The required software elements are defined and integrated into the prototype.
• Further context analysis is done to determine if any significant changes have occurred in the users' workplace since Phase 1.

Usability evaluations in Phase 3 can be used to determine whether or not the software is ready to go into production, or if further development and testing is needed.

Key Usability Tests in Phase 3: Heuristics and Walkthrough evaluations and Laboratory User Testing

Phase 4 - Production and Operation

Phase 4 Processes:

• Plans for integrating and testing the product in the "real world" environments for which it is intended are developed.
• Plans for "final" product delivery and installation are developed.
• Product maintenance and support plans are developed.
• Processes for disposing of the product when it is no longer viable are defined.

Usability evaluations in Phase 4:

• Can guide product revisions, marketing and delivery plans, and the support services required.
• Lead to product updates that require another round of usability evaluation thus repeating the usability engineering life cycle.

Key Usability Tests in Phase 4: Field User Testing