In the last blog post we discussed the Goal Tree. The Goal tree has become one of the critical tools that we use to help make rapid improvements. The Goal tree is not traditionally in the Six Sigma Body of Knowledge but has been part of the Theory of Constraints Thinking Process as the IO Diagram.

We promised we’d talk about a case study where we have used the goal tree.

Remember that the General Structure of the Goal Tree is as per the Diagram below:

Goal_Tree_Generic_Diagram V2

The Goal Tree is based on what is called ‘Necessity Based Logic’ and is read like the following, “In order to Achieve the Goal, I must have Critical Success Factor 1, Critical Success Factor 2, Critical Success factor 3 and Critical Success Factor 4”. The Critical Success Factors, are the high level requirements that must be in place before the goal can be achieved. Each of the Critical Success Factors must be in place before we can achieve the ultimate goal.

Then the next level of the Goal Tree is read “In Order to Have Critical Success Factor 1 (CSF 1), I must have Necessary Condition 1 AND Necessary Condition 2. In Order to achieve CSF 2 I must have NC 3” and so on.

In our case study we will look at the Goal Tree developed for a client with a small Good receiving and dispatching operation. As background, Goods would be received into a warehouse, entered into a Inventory system, checked for goods Certification requirements, then the system generates a new order (or manifest), the manifest is prepared onto pallets or boxes and then finally dispatched to the field operations. Note that we have simplified this case study to enhance clarity.

The goal of the project was very clear “to reduce Manifesting cycle time from over 10days to less than 5days”. In this case the goal was stated very clearly with a baseline (or historical) performance, a target and process that would be the target for improvement. This project was started because there was an expected 100% increase in demand over the coming 12 months.

The next step was to determine the boundaries of our ‘system’. In this case this was clear as this warehouse operation was separate and distinct from the organisations main supply chain distribution operations.

We then spent a day talking to staff who worked in the process and more importantly observing the processes and operations. During the observations we were looking for anything that prevented the process from ‘flowing’, moving or obstructing smooth operations.

It became clear that there were some very simple issues like layout, and documentation but more complicated problems that completely stopped the process. These complicated problems completely stopped the process flow and took many hours to resolve. We were able to determine that these delays significantly reduced throughput of the whole operation.

The goals tree developed was shown below: We have removed some of the Necessary Conditions to provide clarity.

Goal_Tree_Cross Dock

This tree should be read “In order to reduce Order Receiving to Dispatch cycle time we must ‘Maximise flow though Receiving’ AND ‘Maximise flow through Processing’ AND ‘Maximise flow through Manifesting’ AND…….

The next level of the tree should be read (and well only take a look at the first Critical Success Factor) ‘In order to Maximise flow through Receiving we must improve the layout of Incoming Goods Operation AND Standardise incoming documentation AND Triage orders with problems AND…..”

We could have drilled down to the next layer (which we did in this case) to have actionable steps that must be implemented to achieve the higher level of Necessary condition. From here it was very easy to develop the project plan

The Goal Tree provided a ‘plan on a page’ and provided a quick and easy talking point for validation with the project team and senior management. One technique we have further used to improve the tools effectiveness is to colour code the Necessary conditions. We use red for a NC that is not implemented, yellow for items that are being implemented and green for NC’s that are implemented and in control. This makes the projects implementation status very quick and easy to determine.

We recommend the ‘Goal Tree’ for all projects and find that senior management like the clarity it provides, particularly during project reviews.