Principle 2: Quality is in the eyes of the beholder
There is no one definition of software quality. To developers, it might be an elegant design or elegant code. To users who work in stress environments, it might be response time or high capacity. For cost-sensitive projects, it might be low development cost. For some customers, it might be satisfying all their perceived and not-yet-perceived needs. The dilemma is that these may not be all compatible. Optimizing one person’s quality might be detrimintal to another’s. (This is Weinberg’s “Political Dilemma” principle.) A project must decide on its priorities and articulate them to all parties.
References
[1] Weinberg, G., Quality Software Management, Vol. 1: Systems Thinking, New York: Dorset House, 1992, Section 1.2.