This second part to the previous post will look at an example of mind mapping an evaporating cloud diagram. I’ll begin with uncovering a conflict to achieving a goal then examining the underlying assumptions to find the bad premise.
Uncovering Conflicts with a Current Reality Mind Map
One of the techniques introduced in Goldratt’s Thinking Process is constructing a Current Reality Tree (CRT), which shows how a goal depends on necessary requirements which may have their own prerequisites. As an example, consider the following (simplified) CRT for profitable products:
Since we’re using a mind map as a drawing tool, the usual CRT arrows are missing, but the interpretation is the same: child nodes are conditions that if met then result in the parent node. For example, if our “design is flexible” and we have “rapid customer feedback” then we will achieve “fast time-to-market”. A full-blown analysis would, no doubt, have other necessary requirements (like “good execution”).
In the above example the contradiction of a flexible and frozen design is highlighted. This is a source of conflict that can impede progress towards the goal.
Check Your Premises
The next step is to extract the Evaporating Cloud and list the underlying assumptions. The contradiction exists because at least one of the assumptions is wrong.
Here’s the new mind map:
Some further thought will uncover more assumptions, but all we need now is to find a few bad ones. Some questionable assumptions are:
- “Changing designs cause havoc in the supply chain”- What’s missing that can alleviate this problem?
- “Need to scale the supply chain now”- Really? Are we sure we have a product customers want?
Inject New Requirements
The above questions lead to adding (“injecting” in TOC-speak) two new requirements to fix the bad assumptions:
- Supply chain disruption can be minimized with a good change control process that clarifies effective dates, disposition of inventory, and build schedules.
- Don’t scale the supply chain until the demand for the product is validated
Once these requirements have been added, you should go back a see if they create any new conflicts that need resolving.
But That Was Obvious, Right?
Well, maybe- but notice that many organizations have exactly this conflict of missions between product development (want maximum variation) and manufacturing (want no variation). If even this simplified example raised this, there is plenty of room for (continuous) improvement in real life!
I’m interested to see any applications you may care to share…