What is the 5S system?
- S – Sorting (jap. Seiri)
- S – Systematics (jap. Seiton)
- S – Cleaning (jap. Seiso)
- S – Standardization (jap. Seiketsu)
- S – Self-discipline (jap. Shitsuke).
1.S. – Sorting products in the refrigerator
2.S. – Systematizing the layout of products in the refrigerator
- Do not store open milk on the refrigerator door. As a result, it will undergo frequent temperature changes, and its shelf life will be much shorter than assumed.
- Store vegetables and fruits in the bottom, closeable drawers. The temperature in them is around 10 degrees Celsius. It is perfect for fruit and vegetables. Importantly, it is more humid there – like in a cellar.
- Store short-lived products on the middle shelves. The temperature here is optimal for keeping cheese, meat and yoghurt fresh.
- Store long-term products in a warmer place in the refrigerator. Usually these are the top shelves. In my refrigerator, the airflow is from the top (which is unusual), so the lower shelves are warmer. This is where you should store jams and preserves. Where it is colder, things will deteriorate faster. Good acidifying bacteria grow at a higher temperature, and harmful putrid bacteria at a lower temperature.
- Keep products that are happy in low temperature as close to air as possible. It’s the top shelf in my refrigerator. It’s the perfect place for beer, milk or juice.
3.S. – Cleaning the refrigerator and preparing its autonomous maintanace
4.S. – Standardization of using the refrigerator
- A two-container Kanban system for eggs (Figure 5). Thanks to this, it is easy to manage the number of eggs in the refrigerator. Eggs should be taken from the green zone. When it is empty, remove the container and put the second container with eggs from the red zone on the green one. The empty egg tray is placed on the red zone in the free space. For a person doing shopping, it is a sign that you need to refill it – buy eggs.
- Labels with the expiry date for open products and the determination of the direction of material flow in accordance with the FIFO principle (Figure 6). The developed standard says that when a product is opened, the date to which the product can be safely used is written on the self-adhesive label. The label is then attached to the product. Of course, this date is entered based on the recommendation of the manufacturer of the product. The arrows drawn on the stickers are meant to show the direction of adding products to the refrigerator, so that those with the shortest expiry date are closest to the person using the refrigerator.
- Preparation of containers for meat, vegetables and fruits (Figure 7). The standard says that after shopping, we should not put these products in the refrigerator, but instead put them into special containers that extend their shelf life. Of course, the containers are also marked with the aforementioned expiry date labels.
- The Kanban system for managing the stock of milk cartons (Figure 8). The rule is that the refrigerator can contain a maximum of two cartons, of which only one can be open (green box). After it is used, the empty box is thrown into the bin, and the box from the red zone is placed on the green zone. The red zone informs a person that a new carton of milk should be added (buy it or take it from the storage from outside the refrigerator).
5.S. – Self-discipline in maintaining the developed standards in the refrigerator
- Only put your things in the designated places.
- On each opened product that has an expiry date, attach a label stating when it should be consumed by.
- Follow the schedule and cleaning instructions for the refrigerator.
- If any place in the refrigerator gets dirty, clean it immediately.
- Follow the FIFO rules.
Dr. Bartosz Misiurek is a founder of Lean Community and Lean Management Token. He is a CEO at LeanTrix Global Company and a Member of the Board at Astral Hodling OU (IT Company). Author of the book “Standardized Work with TWI: Eliminating Human Errors in Production and Service Processes.” He works as Sr Manager at Automotive Company.