How do ‘OEE waterfall reports’ make production ‘added value’ visible?
Ask production staff how well the morning run has gone and the conversation could go one of several ways. “It was OK, we managed to get the order out” or “It was terrible, everything that could go wrong went wrong”. Neither are particularly helpful to a maintenance or continuous improvement team trying to get to the facts to assess what really needs to be done.
The OK comment could easily be hiding a multitude of problems – we may have managed to meet the order demand, but at what cost? I remember talking to one first line manager who felt the first six hours of the shift has been OK but had not realised 90 minutes had been lost through a variety of speed losses and stoppages. 90 minutes lost in six hours is probably not 'OK' by most measures.
The “everything went wrong” comment is probably worse, “it’s making a funny noise” doesn’t really help the maintenance team when they arrive, especially when the noise has already stopped, but I suppose it’s a start.
Step forward, the "OEE Waterfall" technique. When the technique is applied to OEE it becomes a consistent and user friendly way of showing the real impact of production performance. A waterfall might appear to be an unusual model on which to base an OEE production report but when the object of the exercise is to reduce wasted time in the production process it’s a good way to visualise how well, or how badly, things are working.
The OEE waterfall graph for a food manufacturer
The OEE Waterfall graph above is showing one day of a food manufacturer.
Plan - our production aspiration, the time we intend to run the plant to fulfil the order demand, they are planning to run for 18 hours per day.
Planned – Planned downtime has been scheduled in and would cover off product changeovers, breaks etc.
Short stoppages – Short line stops - these can be particularity damaging for OEE.
Variance to standard – Poor product.
Waiting for internal – Waiting for internal resources, this will drill down to labour, ingredients etc.
Added value – ‘Added Value’ the true point of the exercise, our production aspiration was 18 hours but we managed to add value to the business for just 9.5 hours.
Baseline captured – time to improve
Once that base line of Added Value time is generating by the capture of accurate information a culture of improvement can be created. Each element that makes up availability, performance and quality can be allocated to groups or individuals as targets for improve. Those elements, and the value added time total, can be reviewed frequently, as least weekly, but to make real progress each shift or each two hour period.
A useful technique I have seen used to very good effect in many campaign rooms is to adopt this pattern for each improvement task:
Agree a blame amnesty; it’s not about fault it’s about resolution
Create a top 5 or top 10 loss wall in the CI campaign room
Take a series of photographs of the loss to be improved
Take a photograph of the person accountable for that improvement
Show the position of that loss by generating a graph of top 5 or top 10 losses
Generate a graph for the specific loss over time, usually thirteen weeks
Document an improvement plan of action to resolve the issue
Record progress and meet weekly to monitor resolution
React to a lack of progress and provide additional support to the person accountable as required
Don’t change direction when things get tough, or change the system
Just keep remembering the effect of a low ‘added value’ score. In the illustration above the factory has funded the assets, labour, materials and energy costs to the tune of 18 hours per day but has only gained 9.5 hours of effective production output, fit for sale, in return. It’s sobering to consider that virtually every improvement that increases that value of 9.5 hours either reduces the loss or goes straight to the bottom line as profit.