In the May/June issue of Parcel Shipping & Distribution, we talked about mapping the value stream to identify opportunities. These opportunities would be identified on the value stream map as a Kaizen burst. A Kaizen is continuous, incremental improvement of an activity to create more value and less waste. Kaizen establishes what needs to be done and instills the principles of continuous improvement. Over the next several articles, we will look at many different lean tools that can be applied to achieve greater value and reduced waste. First, we will look at the Standard Operations (Work) method.
Standard Operations is an agreed upon set of work procedures that establishes the best and most reliable methods and sequences for each process and worker. It is a tool used in cellular manufacturing and pull production to best utilize people and machines while keeping the rhythm of the production tied to the flow of customer orders. Standard Operations aims to maximize performance while minimizing waste at each persons operation and workload. It is important to note that these operational standards are not inflexible. They will be slightly altered or tweaked to meet the daily customer requirements.
Standard Work is used as a diagnostic tool, exposing problems and inspiring continuous improvement. Each person should be continually thinking of ways to improve the way he or she does the work. The culture must support this creative problem solving if standardization is to be achieved. Some of the ways a facility can create this environment is to: 1) Provide training to every operator on improvement methods. 2) Create a system for generating and implementing employee suggestions. 3) Reward operators who make improvements. 4) Allow mistakes and encourage experimentation. 5) Support teamwork and ownership of the process by every operator.
There are methods to create standards in your facility. The first is developing a Standard Work Layout. This is a hand-drawn diagram of the area or cell you are looking to standardize. Once you have drawn the diagram of the area, follow the operator and note all the movements he or she makes to complete the process for that area. Typically, there will be operator movements that are waste, which can be reduced or eliminated. As you plot the movements and sequence, you will notice that the movements create an overlapping or crossing sequence resembling a plate of spaghetti (referred to as a spaghetti diagram). This will give you a good indication that the layout does not lend itself to the most efficient way to complete the process.
The idea is to reduce or eliminate as much walking for the operators as possible, hence reducing their cycle times. This may include changing the order or position of the machines to allow the operators to follow a continuous flow.
Process Standards Sheet
The next method is to create a Process Standards Sheet (which should be one page, if possible), so that operators who need to refer to the standards can quickly see what is required. The process standards should include the following information: 1) Data charts that can be used during operations, using photos and drawings to show complex information. 2) Clear objectives of the standards. 3) Control points, check points and other management data in sentence and symbol form. 4) Categories that divide the must versus the prefer and indicate the ranges of operation, both normal and abnormal. Standard sheets should be placed at the work cell. It is always recommended that you color code the process sheet to provide a better understanding so that adherence can be achieved.
Process Capacity Table
The next method is the Process Capacity table, which documents process capacity per time period. It focuses on total machine time, including loading and unloading. The load/unload and the start of the cycle time should be the only steps used to identify any manual time. You must also document walk time. Combining your manual and machine time will give you your total base time to finish. It apportions any tool change time, which will give you the time per piece. Then you add your base time to finish to the time per piece to obtain your total time per piece. Divide your total time per piece with your takt time in order to determine total capacity. A key point is that this process capacity table does not include any abnormalities in the process.
What are the benefits to standardizing and effectively communicating the process to the operator? 1) Operations become more efficient and reliable. 2) Improved quality reduced inspection costs. 3) Costs decrease due to reduced overtime and materials not wasted. 4) Delivery delays are reduced or eliminated due to the operations becoming more reliable. 5) Employee skills and morale increase as the time it takes to go from a trainee to an experienced worker is reduced.
Where is This Information in My Warehouse?
There are several elements to standard operations that you need to define. The first element is the takt time, which is the total production time available divided by customer demand. This will provide you with the pace production will need to be at in order to be in harmony with the ever-changing customer demand. The time period units you choose must be consistent (i.e., day, week or shift).
Takt time = Total available production time per period
Total production requirements per period
The second element is the cycle time, which refers to the time it takes for an operator to complete one process (i.e., one good part or product). If the cycle time of a complete process can be reduced to the takt time, then the product can be made in one-piece flow. The third component is line balancing, which is a calculation to determine how many operators are needed on each line or cell to distribute work. To find the number of operators needed, divide your total cycle time by your takt time. For example, a total cycle time of 150 and a takt time of 50 would require three operators in order to perform the process effectively.
The other element is Standard Work Sequence, which is the order of tasks involved in an operation to complete an operation cycle. It is important to note that the process sequence and the work sequence may be different, depending on the number of operators in the cell or line. If the takt time is reduced because of a decrease in customer demand for the product produced in that cell, then a single operator will be able to run all of the operations in the cell to keep up to takt time. Conversely, if the customer demand increases for the product produced in that cell, several operators may be needed to keep to takt time. As you can see, the work sequence of each operator will be designed to keep individual cycle times down so that takt time can be met.
In addition, you need to address your Standard Work in Process inventory (WIP). That is, the minimum amount of inventory that is needed for work to progress without creating idle time or interrupted production flow. The kanban system in pull production helps to reduce the amount of WIP to a minimum. Continuous improvement of the standards in the process will allow for the reduction of WIP to minimal levels, with the goal being zero inventory.
These several methods and tools create a Standard Work environment that can greatly benefit your organization. Whether your choose standard layout, standard process sheets or standard process capacity table, you must understand the importance of takt time and cycle time, as well as the critical nature of work sequence and process sequence. Remember, without standard methods, you can not measure the improvement you need in order to help your facility gain control of your processes.
Richard Kay is President of RGK Lean Consulting and has over 16 years of experience in manufacturing and distribution. He can be reached at richard.kay@rgkleanconsulting.com.
Sidebar:
There are methods to create standards in your facility. The first is developing a Standard Work Layout. This is a hand-drawn diagram of the area or cell you are looking to standardize. Once you have drawn the diagram of the area, follow the operator and note all the movements he or she makes to complete the process for that area.
