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Value stream mapping (VSM) helps you visualize all aspects of a product flow through a process, with value added and non-value added activity analysis for optimization of lead time, work balancing, and fulfilling customer demand. Typically, you map the flow door-to-door, or from the supplier to the customer showing both the material flow (of the product or item being produced) and the information flow (of synchronizing information that directs the production).
The goal of Lean value stream mapping and analysis is to eliminate waste and transform a process from a push model to a pull model. In a push model, a process has inventory staged at many points and pushes the product from one step to the next without regard for how fast the next step can consume it. A Lean process employs a pull model, where each step creates only what downstream steps need. In this model, your process stores less inventory at each step, and product changeover transitions are smoother with optimized lead time.
For more information on Lean value stream mapping, see Learning to See from the Lean Enterprise Institute.
For more information on Lean extended value stream mapping, see Seeing the Whole from the Lean Enterprise Institute.
A Timeline displays Value-Added Time (VA, time a customer is willing to pay for), and Lead Time (LT, the amount of time it takes a piece to move through the process) using Lean data elements built into the diagram. This facilitates analysis of the material flow of the value stream. The source of data shown on the Timeline can be a shape defined to be an activity or inventory. A value stream map may have more than one Timeline, and each shape can indicate which Timeline it is using, and whether it is shown on the Timeline. For example, in a service VSM, you may want a Timeline for the current state and one for the future state. Or you may want a Timeline for each facility you are comparing. In an extended VSM, you can map and analyze data for a facility or transportation. The summary box on the Timeline shows the total Lead Time and Value Added Time of the process as well as optionally showing any additional Timeline data or custom data specified.
The Timeline in the Lean Value Stream Map diagram supports Lean standards with the display of overall Lead Time (Total Time), Value Add Time, and Lead Time/Value Add Time on upper or lower segments. Display of data in the upper or lower segment on the Timeline depends on whether the diagram displays VSM data, Extended VSM Facility data, or Extended VSM Transport data, as explained in the table below.
In extended VSM, the Timeline shows in-factory time versus transport time, rather than the VA or NVA shown in a VSM diagram.
iGrafx supports two styles on the Timeline in the Value Stream Map and Extended Value Stream Map. Both styles show overall processing time and, where present, Value Add time for each step represented.
The Value Stream Map style highlights steps that have Value Add time. Value Add steps appear as down steps. If Overall processing time is not equal to Value Add time, it is shown above the Value Add time in the Timeline.
The Extended Value Stream Map style highlights steps by type. Facility/Activity steps display as down steps. If Value Add time is present, it is shown in parenthesis.
The Distance Line helps you analyze the waste generated by unnecessary movement of work items. For example, if parts are moved around on a manufacturing floor, the Distance Line can reveal transportation waste by reporting the actual distances between work stations. The Distance Line totals custom data values of Lean type Distance Traveled for each activity, each inventory, or all Timeline data for each Timeline. If the Lean type Distance Traveled is not used, nothing displays on the Distance Line.
The Distance Line maps the distance pieces travel between steps and reports the total distances graphically on the value stream map.
The Work Balancing Graph displays a graph of Takt Time of the process in relation to Production Time at each activity or step. The graph automatically updates when changes are made to the value stream map data. (Production Time at a step is the time between each piece being produced. For more information, see Enter Data on Value Stream Map Shapes.)
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