It should be mentioned that the focus on waste alone is
rather restricting the scope of Lean: originally, ‘muda’
was one of three concepts: Muda, Muri and Mura. Mura
relates to ‘unevenness’, and argues for stable demand
that enable smooth process flows. The more uneven
demand, the more variation in the process, and the less
efficient the process will be. ‘Muri’ is the term for
‘excessive strain’, which argues for good working
conditions that prevent injuries and strain on the worker
which is a clear factor in reducing absenteeism.
Last but not least, it needs to be mentioned that a
general perception of Lean is that it is only concerned
with waste reduction and subsequent cost reduction.
This is not true, and in fact marks a severe limitation of
the common understanding of Lean, as Hines et al [20]
(2004) note there are in fact two ways in which to
increase customer value: one, by reducing waste and
thus the cost of a product or service, or two, by
increasing the value-adding activities without increasing
the cost of the service or product.
Thus, putting the elements together, Lean can be
defined as:
‘……a management practice based on the philosophy
of continuously improving processes by either
increasing customer value or reducing non-value
adding activities (Muda), process variation (Mura), and
poor work conditions (Muri).’ (Radnor et al, [10] 2011)