A well-known consequence of improving a single process
is that problems shift to adjacent processes. In mental health
care, timely out-patient follow-up after in-patient treatment is
a well-known problem that causes patients to stay admitted
longer, even in well-organized wards. That is why lean
emphasizes a systemic, holistic view of process improvement.
Application of lean thinking may initially focus on improving
a single process (the ward) but needs to rapidly diffuse to the
total value system (the ward and the following out-patient
treatment), otherwise problems are not solved completely
and will occur elsewhere in the system.