DMAIC Project: Improving the Packing Rate of a Cold Storage
Baseline (Define)
The company produces food that is cold-stored and delivered to several distribution points. In cold storage, the food is packed in boxes according to a collection list, which are then organised according to destination for transport. Storage space is limited and packing is a manual process. The packing process is not documented, the items to be packed are spread throughout the warehouse and other cold storage supplies are also stored there.
The company is moving to a 3x/week transport rhythm instead of daily transport. This requires efficient use of space and improved packing speed.
Process performance at the beginning (Measure)
At the beginning of the project, the packing rate was 330kg/h. The packing speed can be calculated from the hours worked in the packing plant and the quantities of food packed. Packing is a manual process, so the time spent on packing per job was monitored over a period of time to identify where the most improvement could be made in the process. For example, direct wastage in waiting time was identified, due to the fact that not all the food to be packed was ready before it was packed.
Improvement measures (Analyze & Improve)
The main root causes were identified as the clutter in the warehouse, which caused moving, searching, organising and unnecessary movement. In addition, waiting sometimes resulted in unnecessary wastage.
The process was described and the steps that involved waste were identified. The aim was to eliminate or streamline these by innovating changes among the project team. Key actions included
- All unnecessary goods were removed from the warehouse
- The layout of the warehouse was redesigned to minimise unnecessary movement and handling.
- In the spirit of 5S, the warehouse was divided into areas with only similar goods. The areas were taped.
- Brief instructions were written for all those entering the warehouse.
The process development was largely done using Lean tools. Six Sigma tools were used to analyse the initial state, identify a representative period of time associated with the initial state, analyse the final state and compare the initial state with the final state.
Results (Control)
Uuden prosessin pakkausnopeus oli 478 kg/h ja varianssi oli alkutilaa pienempi. Muutos keskiarvossa oli tilastollisesti erittäin merkityksellinen (p<0.001). Pakkausnopeuden tehostumisen lisäksi
- food waste is identified daily as part of the process and can be donated
- other goods stored in the warehouse are easier to find thanks to the clear layout and taping in their own areas
- the company has the opportunity to continue its development work
To monitor the level of activity, a packing station daily card was created to monitor that the essential conditions for activity are in place every morning and that the space remains tidy at the end of each day. The daily card also records the time spent in the packing room, making it easy to set a daily KPI (kg/h) and monitor its maintenance. The process owner initiated continuous improvement meetings with the packing staff. It is also easy to try out new changes one by one and monitor their impact on the KPI metric.
Lessons Learned:
- Getting reliable data is not easy or happens without work. Although data systems exist, their support for getting the data out is sometimes even worse than you might think.
- The best ideas come from the people doing the work. An outsider can facilitate the use of expertise already in-house as a neutral facilitator.
- Involving people who work in the process to be improved makes it more effective in getting changes implemented and significantly reduces resistance to change.
This project was a Black Belt training project, which the participant did as part of the training and received a Black Belt certificate at the end of the project.
If you are interested in learning how to improve your processes using Lean and Six Sigma, and earn your Belt Belt certification at the same time, check out the training at the link: Black Belt training.