Production planning and control in mass production
Mass production
Only one type of product or maximum 2 or 3 type of products are manufactured in large quantities and much emphasis is not given to retail consumer orders. Standardization of products, processes, materials, machines, uninterrupted flow of materials are the main characteristics of this system. Example: - petrochemical industry, cement industry, steel industry, sugar industry, cigarette industry etc.
Features of mass production system
o It includes manufacturing of high volume standardized products.
o There is a smooth flow material from one work station to another workstation.
o Production time of production unit as a whole is short (i.e. because of specialization principle).
o Closely spaced work station reduce material handling.
o Production planning and control is simple.
o Work in progress inventory is less.
Production planning and control is possible under mass production only with the help of line balancing.
Production planning and control in mass production
It is usually far simpler than in a job or batch production. Extensive effort is required for detailed planning before production starts, but both scheduling and control need not be elaborate usually. The output is either limited by available capacity or regulated with in given limits to conform to production targets, based on periodic sales forecasts.
Planning problems in mass production
Setting the rate of production from line and arranging the various production centers on the line accordingly. Line balancing helpful in equalizing output rates from various work points in mass production line and in reducing idle time of labour.
Process Production planning and control in mass production( with example)
1. Define the tasks e.g. a,b,c,d,g,h.
2. Identify precedence relationships/ requirements or draw precedence diagram for these task.
3. Calculate minimum number of work station required:
Minimum no of work station =
=maximum allowable cycle time per unit / time allowed at a work station per unit
= say 380 seconds/ unit
90 seconds / unit
= 4.22 stations = 5 station
4. Assign task to different stations on some basis or principle or rule. One such rule is longest operation time (LOT) rule – giving top priority to task that has longest operation time.
Steps: -
LOT (1) first assign the task that takes most time to the first station while maintaining precedence requirement.
LOT (2) after assigning a task, determine how much time the station has left to contribute.
LOT (3) if station can contribute more time, assign it a task requiring as much time as possible while maintaining precedence other wise return to LOT (1) and continue same steps until all task have been assign to different station.
5. Evaluate effectiveness and efficiency
(Effectiveness – if desired capacity is achieved)
(Efficiency- labour utilization)
Calculation of labour utilization efficiency for proposed 90 second lines.
6. Seek further improvement by changing time.
Mass production
Only one type of product or maximum 2 or 3 type of products are manufactured in large quantities and much emphasis is not given to retail consumer orders. Standardization of products, processes, materials, machines, uninterrupted flow of materials are the main characteristics of this system. Example: - petrochemical industry, cement industry, steel industry, sugar industry, cigarette industry etc.
Features of mass production system
o It includes manufacturing of high volume standardized products.
o There is a smooth flow material from one work station to another workstation.
o Production time of production unit as a whole is short (i.e. because of specialization principle).
o Closely spaced work station reduce material handling.
o Production planning and control is simple.
o Work in progress inventory is less.
Production planning and control is possible under mass production only with the help of line balancing.
Production planning and control in mass production
It is usually far simpler than in a job or batch production. Extensive effort is required for detailed planning before production starts, but both scheduling and control need not be elaborate usually. The output is either limited by available capacity or regulated with in given limits to conform to production targets, based on periodic sales forecasts.
Planning problems in mass production
Setting the rate of production from line and arranging the various production centers on the line accordingly. Line balancing helpful in equalizing output rates from various work points in mass production line and in reducing idle time of labour.
Process Production planning and control in mass production( with example)
1. Define the tasks e.g. a,b,c,d,g,h.
2. Identify precedence relationships/ requirements or draw precedence diagram for these task.
3. Calculate minimum number of work station required:
Minimum no of work station =
=maximum allowable cycle time per unit / time allowed at a work station per unit
= say 380 seconds/ unit
90 seconds / unit
= 4.22 stations = 5 station
4. Assign task to different stations on some basis or principle or rule. One such rule is longest operation time (LOT) rule – giving top priority to task that has longest operation time.
Steps: -
LOT (1) first assign the task that takes most time to the first station while maintaining precedence requirement.
LOT (2) after assigning a task, determine how much time the station has left to contribute.
LOT (3) if station can contribute more time, assign it a task requiring as much time as possible while maintaining precedence other wise return to LOT (1) and continue same steps until all task have been assign to different station.
5. Evaluate effectiveness and efficiency
(Effectiveness – if desired capacity is achieved)
(Efficiency- labour utilization)
Calculation of labour utilization efficiency for proposed 90 second lines.
6. Seek further improvement by changing time.
gud one thnx for the help
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