This book aims at dealing with requirements engineering and management from a true systems approach. This implies the assessing of requirements from the technical, the financial and the legal dimensions. Requirements state what stakeholders need or expect from a system that is to be designed and developed, to fulfill an identified need or opportunity. Normally the focus is on the technical side, neglecting the financial implications of the stated requirements. Even if there are cost-related requirements, the financial derivatives of many requirements of a technical nature are frequently overlooked. If the financial domain is in general a weak spot for people with a technical background, which are normally the ones engaged in engineering projects, the legal world is uncharted territory for most of them. The problem arises when the identified capabilities are to be stated in the form of requirements that will be part of a legally binding document. A real systems engineer is to have a proper understanding over a sufficiently broad array of disciplines. Otherwise, it is difficult to apply the global view that characterizes the systems approach. This book tries to connect the technical, the financial and the legal facets when dealing with requirements engineering and management. That facilitates a true systems approach. In addition to the theoretical foundation presented, a case study is presented to illustrate how requirements are to be dealt with and written. Stakeholder requirements are engineered, and to better portray how they are to be specified, a number of ill-defined or wrongly formulated requirements are presented indicating what it is that makes them inappropriate the way they are worded and how they should have been written instead. Far too many projects end up engrossing the already-large statistics of those that end up exhibiting underperformance, time delays and/or cost overruns. In many cases, the root cause lies with requirements that have been incorrectly specified. Hopefully this book will contribute to a better formulation of requirements, which will itself increase the likelihood of successful project completion.