36. Process Variables (Input/Output) Map Overview A Process Variables Map or otherwise known as an Input/Output Map is a graphical representation of the process. It is typically used as the primary tool to identify all the Xs in a process. It is crucial to identify all the Xs using this tool, because no other tools appearing later are designed for the same purpose. If the Team misses an X now, it is not identified to be considered later. Logistics This is a Team activity and should include representation for all the key areas affecting the process. Choose those individuals who live and breathe the process every day, not just Process Owners who might not be close enough to it to know the details. The activity typically takes a total of a morning to complete. It is best to create the map physically on the wall using flipchart paper and sticky notes, rather than directly into a piece of software, such as Visio. Using software makes it tricky for all the Team to participate. A common mistake is for the Belt to want to create a straw man of the map first and bring that to the Team meeting to finalize construction. This approach creates problems with Team involvement and buy-in to the result. The recommended approach is to construct the map from scratch during the Team meeting. Roadmap The roadmap to constructing a Process Variables Map is as follows: | | Step 1. | The Team should revisit the SIPOC first to ensure that they fully agree on
The scope of the process in handThe Team must agree on the beginning and end points of the process. Be specific and don't assume that this is obvious. Try to use unambiguous triggers when the process starts and ends. Often it's useful at this stage to clarify the entity that runs through the process too. The key performance measures, sometimes known as KPOVs or YsOften it is useful for the Team to imagine that they were outsourcing this process, and, if so, how would they measure the performance of competing suppliers. These should have been more fully defined from the Customer Requirements Tree. Sometimes a complex process is in place to deliver little or simple output. Clearly a good question to ask at this stage is "Do we really need this process at all?" The major inputs known as KPIVs or Xs to the processThese are typically raw materials, labor, information, and energy in some form.
| | | Step 2. | List the primary process steps (one per sticky note) to achieve the process as defined in the SIPOC and place them in a vertical line down the middle of the flipchart paper (as per Figure 7.36.1). The steps should exhaustively describe the full scope of the process (i.e., don't miss any steps, particularly at the beginning and the end of the process).
Figure 7.36.1. Process Variables Map under construction. 
The level of detail here is usually the biggest stumbling block in the construction. Typically processes have 510 major steps in their Process Variables Map. It would have to be a large and complex process to warrant any more than that. Also note that every step should contain at least some VA or Business VA, or in other words don't create a process step called "Delay."
| Step 3. | Starting at the first step in the process, list all the outputs and measures of performance (KPOVs) for each step on one or more sticky note. Some of these should align with the major outputs of the whole process as defined in the SIPOC. If all major Ys from the SIPOC do not appear at least somewhere at the detailed level in Step 3, then a major process flaw has just been discovered (i.e., the process is required to deliver something that doesn't appear anywhere along the way through it). This happens more than we care to admit.
Continue step by step through the process until all process steps are complete.
| | | Step 4. | Starting again at the first step of the process, list all the inputs (Xs) to each step (step by step), both physical entities and factors that affect the output of the process step. For physical entities, don't just list the name of the entity, list the Xs that describe what it is about them that affect the output. For example, if water is the entity, then Xs could be water feed rate, water temperature, and so on. One key example of this to ensure is done correctly is listing Operator as an X. What is it about the operator? Is it technical competency, experience, handedness (left or right), age, height, whether they wear glasses, and so on? Xs need to be specific enough to be actionable. In Figure 7.36.1, for example, the Order Processor's skill level and availability are the factors that affect their ability to enter the order. In this case, the Team might have considered others such as eyesight, ability to concentrate, distractions, and so on.
Continue step by step through the process identifying all the Xs until all process steps have been completed.
Items to note are that outputs (Ys) of one step can be the inputs (Xs) to the next and the same Xs can also appear in multiple steps.
Although Figure 7.36.1 shows only part of a Map and, therefore, a limited number of Xs, a completed Process Variables Map has somewhere from 100 to 400 Xs in it and takes up at least two flipchart pages.
One major pitfall here is for the Team to discount Xs (filter them out) at this stage. The Map is a tool to identify all the Xs. No Xs should be filtered at this stage; that comes later with the Cause & Effect Matrix and so on.
| Step 5. | For each X, identify whether the X is currently controlled C or uncontrolled U. The key word here is currently. All Xs are theoretically controllable in some way, even gravity, provided you had enough money to do so. The important question is whether or not you successfully control or even choose to control the X at the present time.
It is often useful to include the third, intermediate category of Standard Operating Procedure SOP. This is a weaker version of "Controlled" because, in effect, you have set the expectation that the X is maintained at some level, but it is at the operator's discretion to do so.
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Interpreting the Output There is little interpretation required for the output of the Process Variables Map because the tool is used only to identify all the Xs and no decisions are made at this point. Some texts recommend taking action directly from the Map relating to the lack of controls on an X. Clearly this is feasible, but it is questionable based on whether or not the X has been identified as being important (at this stage in any roadmap, this is not usually the case). |
