Improving Productivity on the Production Line of a Manufacturing Process Using Lean Model
In this paper, the production line of a company manufacturing metal file cabinets was under-studied with the aim of improving productivity. Lean was deployed with reference to data obtained from a case study company. Material and information flow for the current manufacturing process was studied and designed with the help of Value Stream Map (VSM). Reduction in Lead time was used as a measure for improvement in productivity. The current process had a total cycle time (time taken to process a part) of 8.45 hours and lead time (time an item spends on the floor before being shipped to clients) of 11.3 hours, average order of 240 cabinets monthly from clients. Value stream map was used to study the process flow and one of the production processes (Assembly 1) was found to impact productivity negatively. Assembly 1 was eliminated from the production line because it consumed valuable time of 2 hours and manpower energy. The efficiency of each production stage was measured by how much each impacted the production process. MATLAB and Python programming were used in running the 2k factorial analysis, studying the level of variations within the factors, and studying the effect on the entire system. A new sub-process line (comprising Shearing 1, blanking 1, stamping 1 and forming1) was designed using Value stream map to enhance material and information flow and productivity. With assembly 1 process removed and new adjustments made, the total daily lead time was reduced from 11.3 hours to 6.6 hours and total daily circle time from 8.45 hours to 5.05 hours. Production foremen were reassigned to new roles. The methods and findings of this research if implemented would enable the company to afford producing more than the monthly average of 240 cabinets, and could be used as a template for other local manufacturing companies that desire to go Lean.