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PRODUCTION AND OPERATIONS
MANAGEMENT
Chapter 15SHOP FLOOR PLANNING AND
CONTROL
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
Control
Shop floor planning and control:
• Principles and techniques required to plan, schedule, control and evaluate the effectiveness of production operations.
Concerns of Production Activity Control
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
Control
Production activity control is concerned with:• Priority Control• Capacity Control.
• Objectives of Production Activity Control1. To know the current status of the job2. To determine what should be the next job to be processed and in which
work centre.3. To maximize operational efficiency4. To minimize work-in-progress inventory.5. To minimize set-up costs.6. Minimize set-up cost7. To maintain control of operations by monitoring job status and lead
times, measuring progress and indicate corrective action when necessary
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
Control
Operations Planning and SchedulingThe various terms used in operations planning and scheduling are described briefly.1. Loading: Assignment of jobs to various work centres or
machines for future processing.2. Sequencing: The process of determining the sequence of
processing of all jobs at each centre or machine.3. Detailed Scheduling4. Expediting: The special effort or action needed to keep the job
moving through , the production facility on time as per the detailed schedule.
5. Input-output control: Managing work flow and queues at work centres.
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
Control
The Operations Planning and Scheduling System
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
Control
Elements of Scheduling
i. Demand forecasts/customer’s firm ordersii. Aggregate scheduling iii. Production plan iv. Master production schedulev. Priority planningvi. Capacity planningvii. Facility loading or machine loadingviii. Evaluation of workloadix. Sequencing
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
Control
Scheduling and Shop Floor Decisions in Process - Focused Production System
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
Control
Scheduling Techniques for Job Shop1. Forward scheduling 2. Backward scheduling• Forward Scheduling: From some point in time• Back ward Scheduling: Scheduling by working
backwards from the due dates.
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
Control
Stage in Scheduling
1. Loading 2. Dispatching1. Loading: The assignment of jobs to processing centers.2. Dispatching: Sequencing and selecting jobs waiting at a
Work Center when Capacity becomes available.a. Finite loading: Jobs are assigned to work centers
taking into account the capacity of the work centre and job processing time.
b. Infinite loading: Jobs are assigned to work centers without regard to the capacity of the work centre.
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
Control
Load Charts and Machine Loading Charts
Load chart: A Gantt chart that shows the loading and idle times for a group of machines or Work centers.
Gantt chart: Chart used as visual aid for loading and scheduling purposes.
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
Control
Priority Sequencing
Priority Sequencing: Determining the priority for all the jobs waiting in a queue by applying priority sequencing rules.
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
ControlSingle-Criterion Priority Sequencing Rules
Some single-criterion priority sequencing rules are:1. First come first served (FCFS)2. Shortest processing time (SPT) or shortest - operation time (SOT) or
minimum processing time (MINPRT).3. Longest processing time (LPT) or longest - operation time (LOT)4. Least slack job (LS) first or minimum slack (MIN SLACK) job first.5. Earliest due date (EDD) job first6. Truncated shortest processing job first (TSPT)7. Preferred customer order (PCO) first8. Random selection (RS)9. COVERT (Cost over time)10. Least change-over cost.
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
Control
Dynamic Sequencing Rules (Combined Criteria Rules)
a. Dynamic slack (DS) rule
b. Dynamic slack per remaining operation (DS/RO) rule.
c. Critical ratio (CR) rule.• Scheduling ‘n’ jobs on ‘m’ Machines (m = 2 or 3)
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
Control
Johnson’s Rule or Algorithm
Johnson’s Rule: Technique for minimizing cycle time for a group of jobs to be processed on two machines or at two work-centers.
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
Control
Scheduling Product Focused Systems
Two techniques used in resolving scheduling-related problems in product-focused production systems are:
i. Batch scheduling
ii. Scheduling and controlling production for delivering schedules.
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
Control
Economic Batch Quantity (EBQ) or Economic Run Length (ERL)
a. Set-up costs i.e.,, costs/unit which decrease with batch size.
b. Inventory carrying cost which increases with batch size.
Case 1 : Instantaneous supply with no simultaneous consumption:
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
Control
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
Control
• Case 2 : Non-instantaneous
supply with simultaneous consumption
• Determination of EBQ
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
Control
Scheduling and Controlling Production for Delivery Schedules - Line of Balance
(LOB) Method
Line-of -Balance Technique: A technique used in production scheduling and control to determine at a review date, not only how many of an item should have been completed by that date, but also how many should have passed through the up-stream operation stages by that time, so as to ensure the completion of the required delivery schedule.
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
Control
Line Balancing
Line Balancing: Arranging a production line so that there is an even flow of production from one work station to the next, so that there are no delays at any work station that will leave the next work station with idle time.
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
Control
Line Balancing Procedure in Assembly Layouts
i. Step 1 : Determine what tasks must be performed to complete one unit of a finished product and the sequence in which the tasks must be performed. Draw the precedence diagram.
ii. Step 2 : Estimate the task time (amount of time it takes a worker to perform each task).
iii. Step 3 : Determine the cycle time (the amount of time that would elapse between products coming off the end of the assembly line if the desired hourly production were being produced.)
iv. Step 4 : Assign each task to a worker and balance the assembly line. This process results in determining the scope of each worker’s job or which tasks that he or she will perform.
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
Control
• Determination of cycle time (CT)
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
Control
Determination of the Ideal or Theoretical Minimum Number of
Workers Required in the Line
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
Control
Balancing Efficiency
• An efficient line balancing will minimize the amount of idle time.
• The balance efficiency can be calculated as:
Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat
Chapter 15Shop Floor Planning and
Control
Line Balancing Methods
The various line balancing methods or techniques used are:
1. Heuristic methods
2. Linear Programming
3. Dynamic Programming
4. Computerised line-balancing
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