Five steps of the iterative development process for mobile applications

The process of developing mobile applications involves many stakeholders and phases. Throughout the process, usability work can be conducted with different methods. The methods vary somewhat but the rationale remains the same: Know the user and involve the user in the process. While the development team conducts some parts of the process, usability experts should conduct other parts.

Phase	Usability actions
1. Requirements definition The idea and concept of the application is defined and validated. Some critical element of the application idea may need to be modified. If there is no actual user need or potential commercial interest, the entire concept may be abandoned. In this phase, the various requirements for the application are defined, including usability requirements.	Expert analysis: Find out and correct critical flaws in the concept. Competitive analysis: Study how users are currently using competitive products. User and task analysis: Find out if users are interested to use and buy the product. Focus group: Discuss with a group of potential users to study attitudes towards the concept. Usability Requirements: Define what are the usability measures the end product must fulfill.
2. Design and implementation Functional, technical, and usability specifications for the implementation are defined, based on the requirements. Then the design is implemented as specified. This phase is returned to multiple times after the testing phase, until the product meets the requirements set for it. The design work should be documented carefully. Quality assurance should be carried out by reviewing each iteration of the design.	Usability design: Use guidelines and checklists to verify that the implementation does not violate existing standards. Use design patterns to avoid common problems. Expert analysis: Evaluate prototypes on how to improve the user interface and avoid problematic designs. Individual or group usability testing: Testing paper prototypes or actual product prototypes with real users. Consulting: Avoid delays in the development process by consulting usability experts on specific areas.
3. Testing The system is tested thoroughly to make sure it meets the technical and user requirements set at the beginning of the process. It is very important to conduct also system-level testing, that is, testing also installation, deployment, and configuring the application.	Expert analysis: Make sure the user interface is functional, without severe flaws and receive improvement suggestions. Individual or group usability testing: Find out how real end users use the application and where they have problems.
4. Release to the public After the application has passed testing, it is released for distribution. Research is needed to find out about user acceptance, and what functional, technical, or usability components can be added or improved for future releases.	Satisfaction survey: Receive statistical information on which parts of the application users like and which need improvement. In addition, the effects of possible usability problems can be evaluated. User analysis: See how well the product fits into the user group for which it was intended.
5. Maintenance The product may require changes or updates, different language versions, or porting to new devices. User feedback and market data can be used to identify and prioritise maintenance effort.	Focus group: How would users modify the application? What would prompt them to update or buy another version? Satisfaction survey: Competition may affect users' attitudes and requirements. In addition, the users have had a longer time to evaluate the application. User and task analysis: See how well the product fits into the user group for which it was intended.

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