Because
more work was performed by local resources, fewer
outside resources were required. The annual strategy
was again revised, this time to have four shutdowns
and eight maintenance linestops. (Linestops were not
needed in the same month as a shutdown.) As a result,
one more day was now available for production, an
increase of another 0.3 percent in productivity.
The other major result
experience was that the equipment reliability and
availability improved significantly over the following
two years. The reduction of approximately 170
equipment downtime hours per year returned another 7
days for production per year, also reducing associated
repair costs and delivery interruptions. Several
factors led to this result: frequent access to the
equipment, new technology projects, and implementation
of predictive technologies into condition monitoring
such as vibration monitoring, thermography, and motor
surge testing.
This area also implemented a
series of speed-up projects. These projects altered
the base condition for comparing reliability
improvements, however over four years, the amount of
equipment downtime per thousand linear feet of
manufactured product reduced by 41 percent.
As indicated earlier, the
process in the example was a continuous discrete
system with major changeovers, sometimes four days
apart. Does this shutdown strategy also work for
discrete manufacturing? Experience from another work
center with a discrete process indicates that this
strategy would indeed work.
The discrete process work center
evolved to a plan of having 2-hour linestops every
other week and a 36-hour shutdown every seven weeks,
based on the overall equipment conditions of its
system. Using the same process as described above, the
key mechanic work ratio was approximately 65 percent.
High equipment reliability was maintained. In this
case, as before, the work communities proactively
approached the shutdown strategy with an open mind to
having short frequent shutdowns and maintenance
linestops. In both cases, more effective work areas
emerged.
