The invisible principles of Lean

New Thinking 8 August 2012 Gareth Evans

In knowledge work, most of the important information needed to continually learn and improve – such as batch size, sequencing of work, cycle times and queues – cannot be directly observed. Many development teams use physical boards and other practices to try to expose important information, but these practices are limited by our ability to interpret the signals. As Deming said, “Experience without theory is worthless”. Without understanding the underlying principles, we risk staring at a blank wall.

"The goal of Lean is to have a system that is optimal to deliver valuable results given the organization's particular resources, needs, and options. Since these factors are always changing, a lean enterprise is always fine-tuning to continually improve." Lean Kanban University

Lean is defined by a culture of collaboration and continuous learning and improvement, where individuals are empowered to make small changes in the way they work to help improve the performance of the organisation. In order to respond to a constantly changing environment, every individual in the organisation needs to help recognise improvement opportunities and undertake them on a daily basis. When changes are successful, learnings need to be propagated through the organisation.

"High-performing idea systems – which the authors define as those that implement 12 or more ideas per employee per year – were found to be a major factor in successful lean initiatives, for three reasons. First, they created a “lean culture” of daily improvement. Second, they addressed improvement opportunities that were difficult for managers to spot. Third, they promoted rapid organizational learning." Robinson & Schroeder

The relationship of practice to principle in knowledge work

If a process is made up of a set of practices based on underlying principles, how deeply do we need to understand those principles in order to recognise improvement opportunities?

In manufacturing, it is possible to observe principles through the many visible and tangible objects that form the basis of work practices. In knowledge work, most of our raw materials are invisible and intangible. In manufacturing, you can see piles of inventory building up and you get tired from moving them around. In knowledge work, queues are invisible and complexity and variation of work makes waste harder to identify. Going to gemba in knowledge work is limited as the underlying principles are harder to reach.

To compensate for the lack of visible information in knowledge work, teams use practices such as physical boards and stand-ups to recognise and react to problems in flow. But creating practices in an attempt to expose principles makes it easy to over-emphasise their status and meaning. The practices that teams adopt can give a false sense of security as it is easy to forget that practices are there to illuminate principles. The indirection between practice and principle in knowledge work means that optimising a practice can have little effect on the flow of work. Practices can make problems more visible – but can also hold teams back when they do not understand the underlying principles.

Principles lead to new practices

Process innovation can be stifled by holding onto practices too tightly. Is is also harder to adapt existing practices and come up with new ones without understanding the underlying principles. Practices help teams work together on a day-to-day basis, but understanding principles leads to innovation around process. In knowledge work, a deeper connection with underlying principles leads to deeper improvement insights.

A single principle can express itself in many contexts or levels within an organisation, extending beyond the boundary of the team. Within each context, more than one practice may exist that supports the underlying principle.

Consider the principle of reducing batch size for example:


Batch size reduction practices


Regular planning sessions allow strategic vision and architecture to evolve continuously rather than arriving in large annual batches


Minimum viable products generate small releases


Small stories finished in a few days

Specification by Example reduces transport batch size of untested code


Smaller commits to source control

TDD reduces transport batch size of untested code


Smaller blog entries


With a deeper connection to the underlying principles, improvement opportunities are more easily recognised. Innovation occurs when practices emerge and change in coherence with principles.

Principles also form a bridge between different contexts within an organisation, with each context having distinct practices, but still being able to communicate and understand other contexts through shared principles.

Principles change less frequently than practices so we can learn and understand them more deeply. Practices help you hit the ball when you first get on the court, but principles allow you to change your technique and develop your own style.

In knowledge work, it is the  invisible principles rather than visible practices that allow the freedom to create an effective Lean culture. The challenge is to turn towards principles as soon as possible on the journey.