Production refers to where raw materials, also known as inputs, are converted into outputs. The main role of manufacturing is to produce services and products required by customers in the most economical and efficient manner (Kumar 1999). Production planning and control are necessary to make decisions regarding the use, acquisition and allocation of resources in production processes with the aim of satisfying customer needs effectively and efficiently. It is used to determine the level of the workforce, assign overtime work, sequence the order in which activities occur, and decide on production quantities (Graves 1999). Planning challenges begin with specifying the customer demand that must be satisfied by the production plan. It is not easy to predict the exact future demand and therefore sometimes future demand is not known (Graves 1999). This results in a company relying on forecasts to predict future demand. It is therefore important for a company to formulate a plan that arises from demand uncertainty. Alternatively, it is important for a company to frequently review forecast numbers in order to update the forecast. This is done using optimization models. It is very important for a company to identify relevant costs in a production planning. It is important to determine the variable costs of production, maintaining costs/transportation costs and setting costs (Graves 1999). In production planning, there are three production systems: intermittent production, unit production and continuous production. In continuous manufacturing, products are made according to a standard process and in a sequence that anticipates demand. It involves large capital investments in purchasing equipment and machinery to produce high-quality products but with less labor i...... middle of paper ......Lean Enterprise Institute, Inc 2009. What is the lean? Retrieved from: http://www.lean.org/whatslean/Mekong Capital Ltd, 2004. Introduction to Lean Manufacturing for Vietnam. Retrieved from: http://www.mengkomcapital.comProduction Supervision Training, 2011. Production Planning and Control. Retrieved from http://yourbusinessprofitability.com/_mgxroot/page_10766.htmlPlenert, 2007. Reinventing lean, Elsevier Inc, p15.TechTarget, 2011. Lean Production. Retrieved from: http://searchmanufacturingerp.techtarget.com/definition/lean-productionTimestudy Institute Inc 2011.Lean Concepts. Retrieved from: http://industrialtimestudy.com/lean.htmlTMD Friction 2011. Lean Management. Retrieved from: http://www.tmdfriction.com/en/company/lean-management-Trent J 2008. End-To-End Lean management, Library of Congress cataloging-in-PublicationData, USA, pp153