Inventory management (IM) software is a software system used for various purposes like for tracing inventory level, orders, sales and deliveries. It can also be used in the manufacturing industry to generate a work order, bill of materials and other production-related documents. IM software is used to avoid product overstock and outages. It is implemented for organizing inventory data that were generally stored in hardcopy form or in spreadsheets previously. Lot-sizing problem (LSP) in material requirement planning (MRP) systems belongs to those problems that industrial manufacturers face daily in organizing their overall production plans. Lot sizing plays an important role in minimization of total cost (i.e. sum of setup and holding cost). Many heuristic methods have been developed to solve LSPs, but most of them are applicable for small instances. Harmony Search Algorithm (HSA) is one of those which are considered to be novel when compared to other metaheuristic algorithms. It is an emerging metaheuristic optimization algorithm, which has been employed to cope with numerous challenging tasks during the past decade as it is fast, time efficient, accurate and effective. Based on the requirements of manufactured goods, MRP refers to the net demand of parts or materials. But these demands without any change may be inappropriate for placing an order or manufacturing. Lot sizing is to coalesce the computed net demand by a certain unit in consideration with the cost reduction and work efficiency. The problem aims to find production planning which takes the minimization of total setup costs and inventory holding costs. In this project, HSA has been applied to solve the problems and overcome the issues.