Mfg Metrics-3e-S 11-24, 24/06, 06/04/07
What is the cycle time in a manufacturing operation?
: As defined in the text, the cycle time
is the time that one work unit spends being
processed or assembled. It is the time between when one work unit begins processing (or assembly)
and when the next unit begins.
What is a bottleneck station?
: The bottleneck station is the slowest workstation in a production line, and therefore it limits
the pace of the entire line.
What is production capacity?
: As defined in the text, production capacity is the maximum rate of output that a production
facility (or production line, work center, or group of work centers) is able to produce under a given
set of assumed operating conditions.
How can plant capacity be increased or decreased in the short term?
: As listed in the text, the two ways that plant capacity can be increased or decreased in the
short term are (1) change the number of work shifts per week
or (2) change the number of hours
worked per shift
What is utilization in a manufacturing plant? Provide a definition.
: Utilization is the amount of output of a production facility relative to its capacity.
Expressing this as an equation,
= actual output quantity
produced during the period of interest, and
is the production capacity during the same period.
What is availability and how is it defined?
: Availability is a reliability metric that indicates the proportion of time that a piece of
equipment is up and working properly. It is defined as follows:
= mean time between failures, and
= mean time to repair.
What is manufacturing lead time?
: As defined in the text, manufacturing lead time is the total time required to process a given
part or product through the plant, including any lost time due to delays, time spent in storage,
reliability problems, and so on.
What is work-in-process?
: As defined in the text, work-in-process (WIP) is the quantity of parts or products currently
located in the factory that are either being processed or are between processing operations. WIP is
inventory that is in the state of being transformed from raw material to finished product.
How are fixed costs distinguished from variable costs in manufacturing?
: Fixed costs remain constant for any level of production output. Examples include the cost
of the factory building and production equipment, insurance, and property taxes. Variable costs vary
in proportion to the level of production output. As output increases, variable costs increase.
Examples include direct labor, raw materials, and electric power to operate the production