Splitting the Data
Once we have time-series data in a capability chart, we would look to see if the
visual pattern changes over time. This indicates that something in the system has
changed. For example, in the capability chart below, which shows daily average end-to-end
time for housing repairs we can see that repairs are taking longer to complete.
CapChart was used to ‘split’ the data (i.e.: recalculate predictably how long, from
the customer’s perspective, it would take to make a repair) and we can see this
created a second capability chart.
The chart led the team to ask the question: What happened around the two times where
things clearly took a step change for the worse? In October 2001 a new management
structure was put in place. New supervisors, keen to be the best in terms of achieving
their performance indicators, unknowingly de-stabilised the system. A month later,
the organisation introduced a call centre, as mandated by government policy, causing
further destabilisation. No one had any idea of any of this until the capability
chart invited the question.
Larger Image
For more information about the thinking that changed to make these stepped improvements,
see Chapter 5, The ‘break-fix’ archetype, in
Freedom from Command and Control.