Cellular Manufacturing Systems (CMS) is an application of Group Technology. Most traditional cell formation procedures ignore any changes in demand over time caused by product redesign and uncertainties due to volume variation, part mix variation, and resource unreliability. However in today's business environment product life cycles are short, volumes and product mix can vary frequently. Thus cell design needs to address these issues. In this paper, Dynamic Cellular Manufacturing Systems (DCMS), Virtual Cellular Manufacturing Systems (VCMS) and Hybrid Cell Layout are discussed along with CMS. Based on the CMS methodologies, classification and comparison few suggestions are presented regarding possible future research directions for the CMS problem for both newly and already established researchers. © Research India Publications.