Case Study 1 – Changeover Times
Our first Lean project was identified by one of their employees working in the Injection Moulding Department. The key challenges for this project were identified as follows.
The Department have one 575 Tonne Injection Moulding tool used to produce plastic moulded parts. This machine often required the ‘mould’ to be changed / swapped out depending on the part required. However, this ‘Changeover’ process was:
- The most time consuming changeover of all 17 machines.
- Slow as a result of the fitting of water cooling pipes.
- Delayed due to the fitting of secondary ejector system.
- Slow because of the mould design and lifting strap.
The Current State
- Machine One is the largest machine in the factory with the largest moulds used. As a result, the team changed these moulds as product demand is required.
- The average time required for a changeover = 5260 Secs / 87.66 minutes.
- The company timed this changeover over a couple of weeks. Then, they recorded the average times on a Gantt Chart / Value Stream Map.
8-Step Problem-Solving Process
In trying to solve a particular problem, we advise using the 8-Step Problem-Solving Process:
- Current State
- Root Cause Analysis
- Select Countermeasures
- Standardisation & Learnings
Glen Dimplex wanted to reduce the changeover times. Consequently, this would increase machine capacity. Most importantly, this would enable the company to become more competitive and more flexible.
Root Cause Analysis
First of all, the company use Root Cause Analysis (RCA) to discover the root causes of the problems. This identified the appropriate solutions. They used the 5 Whys and brainstorming tools.
- Why does it take so long to complete a mould changeover? Fitting of all necessary attachments to make the process work.
- Why do we have to fit the necessary attachments? Because without them, it is not possible to complete the process.
- Why would it not be possible to complete the process? The reason is because the water cooling pipes and secondary ejector system process would not work.
- Why don’t we look at modifying the process of fitting the water cooling pipes and secondary ejector system? Until now, no thought was given to modify the necessary attachments.
- Why has no thought been given to modify the necessary attachments? Lack of thought and vision to modify all attachments and thinking to the process.
The Brainstorming Process / Kaizen Event
Brainstorming allows people to think more freely, without fear of judgement. It encourages open and ongoing collaboration to solve problems and generate innovative ideas. Here are some of the ideas used during their brainstorming process to reduce the mould changeover time:
- Have a replacement mould at the machine before changeover.
- Permanently fix the water pipes to mould to save time.
- Material Handler to carry out colour changes during the mould change.
- Lifting strap and secondary ejector system to be modified.
- Have the tools ready before the mould change.
- Central position for the crane remote control and works orders.
Following the Kaizen Event, the team created an Impact/Ease Chart to decide which ideas to prioritise. The result is a visual representation of where best to assign time and resources. Therefore, we can summarise these four activities as follows:
- Just Do It – these ideas have high impact and are easy to do now.
- Why Not? – these issues have low impact and are easy to address.
- Projects – ideas that have high impact but are difficult to address.
- Not Now – issues that have low impact and are also difficult to address.
We don’t discard any issues as their assessment may change over time as other problems are resolved.
- First of all, the company permanently attached the water cooling pipes to the mould.
- Next, they modified the lifting strap.
- The, they created a central location for work orders.
- Subsequently, the team placed all tools required for the changeover beside the machine before the changeover.
- As a result, conducting SMED and retraining of line changeovers at the mould shop has improved their efficiencies.
- Their work environment has improved during changeovers. Finally, this has helped their 5S Team Score for their area.
Most importantly, the initial changeover times reduced from 87 minutes to 41.5 minutes – a saving of up to 46 Minutes (53% Reduction).
Standard Work is a very powerful but under-utilised Lean tool. By documenting the current work practices, this sets the base standard for what can be improved within the company. As continuous improvements are made, the new standard of work becomes the base for future changes.
- By applying all the ideas generated by the brainstorming event, they can adapt all the moulds.
- This allows them to significantly reduce the mould changeover times and increase their flexibility. The company’s estimated saving in the next 6 months if applied to all tools – 282 Hours / €5K labour savings.
- They estimate average savings on the smaller moulds of up to 35%. These are less complex to complete a mould changeover.
By identifying waste in our changeovers we have:
- Reduced changeover times by up an average of 53%
- Introduced quicker turnaround times thereby improving machine availability.
- Recovered labour costs.
- Removed many other associated wastes.
- Reduced wasted transport and handling / inventory.
- Improved employee work environment.
- Increased 5S culture and environment.
- Value Stream Mapping / Gantt and SMED techniques have highlighted an inefficient changeover process that we no longer use.
We firmly believe that the expertise to develop business process improvements already exist in every organisation. This has clearly been the case in Glen Dimplex. Through their employees’ Lean projects, the company has made significant continuous improvements to their business.
ETAC Solutions has worked with Glen Dimplex to streamline their business and improve their processes. We hope you enjoyed reading about this case study on Changeover Times. You may be interested in reading the two other case studies featured here Case Study 2 – Assembly Line and Case Study 3 – Design Projects. All our case studies are available here.