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Shelf-life ratio is one of the main concepts that Triage Tables use to identify the class of service for the work items. It reflects a ratio between how long it takes to deliver vs. how long you will receive a benefit. In other words, it is the ratio of the lead time distribution range to the lifecycle period.  

Our Triage Tables currently support 5 of the most common shelf-life ratios, which reflect real examples that we have seen in commercial examples over recent years:

Ultra-short (2:1): leadtime – 2 : lifecycle period – 1. 

Example: A seasonal promotion like the St. Valentine’s Day promotional campaign for a hotel. Because it may take about 2 months to prepare the campaign and about 1 month to run. 

Short (1:1): leadtime – 1 : lifecycle period – 1. 

Example: Let`s use our common example of ski or bicycle manufacturers. It may also be applicable for any type of seasonal sports equipment. In this cases it normally takes up to 6 months to develop and design new models. Meanwhile the sales cycle lasts about 6 months.    

Other examples are in technology area, such as video game consoles and cars. For instance, Xbox issue new consoles every 7 years. Which means 1:1 ratio: 7 years to make – 7 years to sell. The same case we can observe in Mazda: a new Mazda 3 model is launched every 6 years. Even though they refresh the model every 3 years adding a minor facelift and interior update, mechanically it remains the same machine. 

Medium (1:2): leadtime – 1 : lifecycle period – 2. 

Example: Our latest Kanban Maturity Model book may be a good example for the medium shelf-life ratio. The new 2nd edition of the book took 1 year to write, copy edit, and design the layout for printing. And it is planned to be on sale for about 2 years before the new 3rd edition will replace it. 

Long (1:5): leadtime – 1 : lifecycle period – 5. 

Example: We can observe a lot of examples in the area of the tech products like TVs, washing and drying machines, fridges. Because it is common there that it may take up to 1 year to create the new model and it will be sold over 5 years. Another example may be the Kanban Maturity Model as a concept. It took for David Anderson and Teodora Bozheva 4 years to develop the model, conduct research and run a beta program, meanwhile the lifecycle of the project is expected to be about 20 to 30 years. 

Extra-long (1:10): leadtime – 1 : lifecycle period – 10. 

Example: These are the examples like a new office building in the city: it takes 4 years to built it and it has 40 years life expectancy. It is a long-term investment with a long pay-off. As well the original Kanban “blue book”: Kanban: Successful Evolutionary Change for Your Technology Business reflects an extra-long shelf-life ratio with 1 year lead time and already a 10 year lifecycle.


To learn more about triage approach for the requests in Kanban – check the “Triage” chapter, Appendix D in Kanban Maturity Model book or access it online using

Download the Triage Tables and Dependency Management Posters here. Learn how to apply triage during advanced Kanban training at David J Anderson School of Management or find your local trainer at Kanban University.