Just in time (JIT) is a production strategy which helps the organisation to achieve and improve the return on investment by
reducing material inventory plus the associated carrying costs. It is a logistics philosophy which is practiced in many
manufacturing companies with an aim of reducing inefficiencies and unproductive time in the production process. However,
earlier research and experience suggest that the interrelationship between JIT and other manufacturing system’s
components such as product design and business strategies are more complex than it is suggested by the traditional JIT
studies. This paper deals with the modelling and simulation in the manufacturing industry where assemblies are made as per
the production forecast. The main objective of this paper is to observe how the Finished Goods Inventory of the assembly
process using System Dynamics methodology and how it can be improved by considering the lead time and the
manufacturing cycle time.