The world is changing rapidly nowadays. Needs of people are updating more rapidly with the accelerating pace of technological changes. In such scenario, demand for the products may not be constant most of the time in the market. Also demand cannot be increasing always. In today's world, technologies as well as fashion styles are changing. Therefore, when a new product enters the market by a branded company, demand increases very fast for the product initially. After some time, it becomes steady and then it disappears quickly when newer version of the product flows to the market. Trapezoidal demand behaves like this, which is analyzed in the book.