Many processes suffer from inefficiency, mistakes, errors, defects, downtime and late delivery due to the waste inherent in them. The waste I’m referring to are:
- Transportation
- Inventory
- Motion
- Waiting
- Over-processing
- Over-production
- Defects
- Safety
These waste exists because most of the time it’s the way the process has always been done and no one questions it or looks for the reason why. These wastes create obstructions to flow in people, products, services, information and materials. If any of these issues plague your process you can start by putting together a current state value stream map (CSVSM) and identifying where in your process these waste occur, then use kaizen to start the journey towards improvement.
The following is a ten step method you can use to analyze and improve your current state value stream.
- First, start with you customer. What are the issues your customer has with the product or service you provide? Are there quality, delivery, or cost issues you need to resolve?
- Second, determine your customer demand. How many products or service deliveries do your customers require on a daily basis? Using this demand you can establish the takt time required for your process, which is the rate at which the customer demands your product or service. Takt time = available net production time / customer demand.
- Third, determine metrics for each process step on your value stream map. These metrics can include:
- Cycle time (C/T)
- Uptime (U/T) or Downtime (D/T)
- Changeover time (C/O)
- Quality level (DPMO) or percent yield
- Forth, identify process steps where cycle times exceed the takt time.
- Fifth, identify the value added and non-value-added activities in each process step.
- Sixth, determine the amount of inventory and work-in-process at or between each process step and convert to days, i.e., 1500 pieces (Inventory) / 75 pieces/day (demand) = 20 days of inventory.
- Seventh, using a process capacity model, populate the chart with the data from your value stream map and evaluate.
- Eighth, identify barriers to flow (bottlenecks, high cycle times, high changeover times, etc.), process steps that have high scrap, high DPMO or low quality yields and mark as improvement opportunities. Identify where pull systems (kanban and supermarkets) would be appropriate
- Ninth, identify opportunities on your value stream map using starbursts and implement kaizen events around those areas to eliminate the waste and create flow and pull.
- Tenth, redraw the value stream in the future state showing the new process after all the improvements have been made. This becomes your future state value stream map (FSVSM) and is what you’ll be working to accomplish.