In the Doctor Nurse principle, the operator creating value is considered as the doctor, he receives tools and goods he needs to do his job from the nurse in this case logistics. For this reason, the doctor can’t do his job without the support of the nurse.
What can we learn from hospitals and how can we adapt it to the lean world.
In hospitals it is crucial that the doctor can fully concentrate on a surgery, the doctor is the single point of contact towards the patient using his tools combined with his training. Everything distracting him from being focused has to be eliminated. In order to give him this capability he needs assistant right next to him. The nurse’s job is to support the doctor and provide him with all equipment, tools and material he needs just in time.
Applying this principle to production is not that hard. To use the doctor nurse principle on the shop floor some requirements have to be met. As mentioned think about the operators as the doctor, they have to concentrate on production. As they are the once generating value for the whole organization by assembling the components which customer are willing to pay for – they need to be placed in the center of all activities – the rest is supportive.
In lean manufacturing this is called the line-back approach. Primary processes are the once that add value so focus on the operation and prepare everything that supports it. The nurse takes care of all other activities, most of the time non-value adding activities but necessary.
Arrange the work station in a way that gives the nurse free accessibility to the work area without disturbing the doctor, i.e. filling up kanban shelfs with new material while simultaneously removing empty boxes.
With the approach of separation of primary and secondary processes in two physical areas none of the process will be interrupted by the other.
In addition, this principle is driving the mindset of the organization to focus on a lean production process and how best it can be supported. If you do so, you will also have the advantage by separating value-adding and non-value-adding activities to find you approaches to minimize the non-value adding activities.
Another way of calling the nurse a nurse is a water spider or in lean terms a Mizusumashi – the inbound material supplier.