Economy engineering major importance in studies of modern way of thinking in economic decision-making, and the purpose of this book to provide engineering principles of the economy and address the bases and the means used as a mode of thinking in the study of engineering projects, and this book has dealt with the principles of engineering economics easily dealt research away from the sports complex and away the principles of statistics and probabilities for the end result that a book which is fit to teach in the university faculties, as well as the reference for engineers who have not previously subjected to such a study.