ü Capacity Management is concerned with supplying the necessary
resources.
ü The question of capacity :
·
How much is
available?
·
How much is
required?
·
How to balance
priority and capacity?
ü Capacity can be defined as “The capability of a worker, machine,
work center, plant, or organization to produce output per time period”.
ü Two kind of resources:
i.
Capacity Available:
capacity of a system or resources to produce a quantity of output in a given
time period.
ii.
Capacity required:
the capacity of a system or resources needed to produce a desired output in a
given time period.
Capacity Requirement Planning (CRP)
Ø Work Center File: is composed of a number of machines or workers
capable of doing the same work.
Ø A work center file contains information on the capacity and move,
wait, and queue times associated with the center.
Ø Move time: the time normally taken to move material from one
workstation to another.
Ø Wait time: the time a job is at work center after completion and
before being moved.
Ø Queue time: the time a job waits at a work center before being
handled.
Ø Lead time: The sums of queue, setup, run, wait, and move times.
Ø Level of capacity:
o
Machine or
individual
o
Work center
o
Plant (
considered as a group of different work centers)
Formula
1)
Available time = No. of machine x
Hour x Days
2)
Utilization = Hour
actually worked x 100%Available hours
3)
Efficiency = Actual rate of production x 100
Standards rate of production
Standards rate of production
@
Efficiency = Standard hours of work produced
x 100%
Hour
actually worked
4)
Rated capacity = Available time x Utilization x
Efficiency
5)
Demonstrated
capacity = Total no.
of days
No. of week
No. of week
6)
Total Standard
time = Set up time + Run time
7)
Capacity
required = (Actual time) x (Efficiency) x
(Utilization)
8)
Actual Time = Capacity required @ Total standard
time
Efficiency x Utilization
Efficiency x Utilization
Problems
1)
A work center
consists of 4 machines each working a 16 – hour day for 5 days a week. What is
the weekly available time?
Solution:
Available time =
No. of machines x hours x days
=
4 x 16 x 5
=
320 hour / week
2)
The work center
in problem 1 is utilized 75% of the time. What are the hours per week actually
worked?
Solution:
Hour actually
worked = Utilization x available hours
=
0.75 x 320
=
240 hour/week
3)
If the
efficiency of the work center in problem 1 is 115%, what is the rated capacity
of the work center?
Solution:
Rated capacity =
Available time x Utilization x Efficiency
=
320 x 0.75 x 1.15
=
276 hour/week
4)
A work center
consists of 7 machines is operated 16 hours a day for a 5 day week. Utilization
is 80%, Efficiency 110%. What is the rated weekly capacity in standard hours?
Solution:
Available time =
No. of machine x hour x day
=
7 x 16 x 5
=
560
Rated capacity =
Available time x Utilization x Efficiency
=
560 x 0.8 x 1.1
=
492.8 standard hour / week
5)
Over a period
of 4 weeks, a work center produced 50, 45, 40, and 55 standards hour of work.
What is the demonstrated capacity of the work center?
Solution:
Demonstrated
capacity = Total no of day
No. of week
=
50 + 45 + 40 + 55
4
=
190
4
=
47.5 Standard hour of work
No comments:
Post a Comment