The converting process from traditional production systems (e.g., Job Shops) to focused (cellular) systems is important as one requirement of global manufacturing to challenge the existing global financial crisis. This represents a big problem and a huge task for manufacturers and academicians which almost most of industrial enterprises around the world are still working as a job shop. This converting process means breaking or dividing the existing functional (process) layout into independently and distinctly focused manufacturing cells to gain on the conversion benefits. To consider this issue, a new methodology of converting job shops into cellular systems is introduced based on the requirements of global manufacturing regarding manufacturing systems design only. These requirements are: responsiveness, reconfigurable machines, mass customization, innovative and manufacturing systems configuration. A complete industrial case study will be used to analyze and explain the proposed methodology in a small-sized job shop manufacturing firm