Summary

In this module, you were introduced to the concept of usability, its assessment and the six user/human-centered design steps to achieve it.  Usability assessment methods used in these steps were presented along with the tools to implement these methods.  Several forms of function and task analyses were presented.  These analyses are critical to the thoroughness and completeness of the user/human-centered design process as they provide the basis of task breakdown for evaluation and documentation purposes.  Function and task analyses are essential Human Factors Specialist tools.  At the end of the module, usability metrics were presented along with guidelines for highly usable systems.

The usability of a system depends upon how efficiently users can access the functionality of a system and use it to meet their task objectives. Highly usable systems are developed through a user/human-centered design process.  This process  begins at program inception and emphasizes supporting the system operator and maintainer task performance needs throughout design, development, and test.  This is accomplished through iterative usability assessments that feed back into design and progressive human-to-system interface refinement.