Sunday, May 13, 2012

Process Planning


Product/Operations Management

Chapter 2.0 – Process Planning

Process Planning – The determining the required input resources, e.g. machines, tools, skilled workers, and methods to be used in the process.

Process Planning is anchored on two concepts:

1.      Process Analysis – the determination of the general flow of materials and work.
2.      Operations Analysis – the determination of specific work content and methods.

Items Operations Managers must consider in process planning:
·        If the operation can completely satisfy the desired output and cost.
·        If quality will be assured.
·        What the manpower requirements are.
·        What specific equipments are needed.
·        If the process flow that has been designed is totally justifiable.
Process Principles
Process Analyst and operations managers, must be guided by the following principles:
1.      Work should move progressively forward.
2.      Duplication of work must be eliminated.
3.      Unnecessary steps and distances should be removed.
4.      Time required to process should be minimal.
5.      Preference of mechanical over manual for routine jobs. 
Methods Engineering
This area of industrial study was pioneered by Frederick Taylor, referred to as the Father of Scientific Management, who made the first recorded systematic approach to methods improvement by postulating that improvements will be identified by dividing a task into individual work elements and studying each element separately.
1.      Methods Study – deals with the simplification of jobs and the development of more economical ways of doing it.
2.      Methods Charts – to enhance the effectiveness of the study, several charts are available for the Methods Analyst & Operations Manager.
3.      Motion Economy – an alternative tool in methods engineering. It emphasizes the importance of making the maximum usage of the human body in the work cycle. It lays stress on gearing the human body to the work process in its most natural movements.   
Work Measurement – Also known as Time Study, it seeks to establish the average cycle time that could be attained by a normal worker performing at a normal level of effort.
In rating the job activity, three methods can be used:
a.      Synthetic Rating – actual observed times for one or more of the job cycle elements are compared to predetermined time standards.
b.      Objective Rating – speed or pace is rated first, ignoring the job conditions. An adjustment is then made to take into account the level of job difficulty.
c.       Westinghouse System Rating – is based on four factors: skill, effort, conditions, and consistency. Each of this factors is rated separately and then combined to give a weighted rating average that will be applied.
After applying the desired rating, allowances must be added to the adjusted work time to derive the standard time value. Allowances can be due relaxation from fatigue, contingency allowances to accommodate unexpected events, and/or unavoidable delays.
Example 2-1
If a job’s standard time is eight hours and a worker actually takes six hours, What is the worker’s Performance Rating?
(Solution)
                   P.R. = Standard Time   x  100%
                                 Actual Time
                      
                           = 8/6 (100%)

                           = 133% (above standard)

Example 2-2
What is the standard time for a job task where the normal time is 4 min.; standard allowance for delays is 1 min.; fatigue allowance, 0.5 mins, and standard allowance for personal time is 0.75 mins?
(Solution)
                 Std. Time = Normal Time + Allowances
                                   = 4.0 + (1.0 + 0.5 + 0.75)
                                   = 6.25 mins.













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