Inventory means the raw materials, work in process goods and completely finished goods that are considered to be the portion of a business's assets that are ready or will be ready for sale. The classic inventory problem involves determining how much of a resources to acquire, either by purchasing or producing it, and whether or when to acquire it to minimize the sum of costs that increase with the size of inventory and those that decrease with increase in inventory. In this book we present some inventory model with deterioration and other effects. The governing differential equations have been solved by Newton-Raphson method. The content of this book is applicable to defence, industries and the researchers, working in the field of inventory.