Usability Means User-Centred Design  

To create usable products you must be user-centred throughout your development process: from setting goals to installation. Two case studies illustrate why this is important. User-centred design is about actively involving users and understanding their requirements. It is necessarily iterative and multi-disciplinary. User-centred design requires commitment from your organisation or your client and yourself. Choosing your activities to match the level of acceptance of usability in your audience will help to create that commitment.

Jarrett, Caroline. STC Proceedings (2001). Presentations>Usability>Audience Analysis