More TXM Lean Glossary



A visual feedback process that indicates a person has a problem in production or in part supply and needs assistance to fix the problem.

How does it help?

Factories have many things going on at once. A good manager doesn’t need to know about everything that is going on – in most cases things will be going okay and to the plan that was set last week and reviewed at this mornings stand up meeting. A good manager needs to know when something abnormal has occurred and the people need help to fix it. The andon systems allows everyone in the factory to look around and check that all is okay or if a problem has arisen. When a problem has arisen, the people tasked to help fix these problems can be mobilised.

The key to effective andon is not which brand of light to install and how annoying the audio signal is that goes with it; an effective andon system needs a timely response. Don’t install lights until you have a process for dealing with the requests it will issue – you need a team with the training and time allocated to properly fix problems as they are highlighted.

Without they effective team in place, either of two things will happen;

1. the extra light “pollution” will be ignored and your workforce will be disgruntled that their promised problem-solving help isn’t helping


2. your workforce will get disgruntled and not even bother using the andon signal to show problem has occurred.

Either way, your money will have been wasted, so think through your response process before worrying about lights.



A process to signal the need for work, either for Production to make something or stores, or supplier, to supply something. For kanban the signal is a physical indicator – it may be a card, an empty box or a returned trolley.

How does it help?

Factories have many things going on at once. A good manager doesn’t need to know about everything that is going on. Tasks like parts supply and sequencing parts at a machine are tasks that can be controlled by a kanban system. The challenge with a kanban system is that it takes good planning and a good knowledge of kanban systems to implement one. Once it’s set up and everyone is trained, it will run smoothly, with little management input.

The naive will then leave the kanban to it’s own devices, presuming that the people who run it everyday have the understanding of what it do if things change or go wrong. The wary and wise will understand that even the simplest kanban system needs regular reviews to check the original assumption and parameters are still being met. Quarterly reviews need to include:

– auditing the kanban cards or containers; are they all present and accounted for?

– reviewing the quality of supplied parts; if too many parts are being scrapped or reworked,this can result in part supply problems

– review customer orders; if demand had greatly increased or decreased, then stock levels will need to be changed accordingly.

Robert Chittenden

Author: Robert Chittenden

Robert Chittenden is a Senior Lean Consultant at TXM Lean Solutions