This is an excellent introduction to formal methods which will bring anyone who needs to know about this important topic up to speed. It is comprehensive, giving the reader all the information needed to explore the field of formal methods in more detail. It offers: a guide to the mathematics required; comprehensive but easy-to-understand introductions to various methods; a run-down of how formal methods can help to develop high-quality systems that come in on time, within budget, and according to requirements.