Operations Management : Line Balancing

This presentation gives us details about the different methods of Line Balancing.
It also gives an example of Ford Motors and how Line Balancing helped Ford become a powerhouse in the early 1900s

1. LINE BALANCING Presented By: Ashita Negi Deepti Verma Nancy Negi Rohan Bharaj Uchit Arora

2. Line Balancing Line balancing is the procedure in which tasks along task the assembly line are assigned to work station so each has approximately same amount of work . A workstation within an assembly line in order to meet the required production rate and to achieve a minimum amount of idle time.

3. Balanced Line Promotes one piece flow Avoids excessive work load in some stages (overburden) Minimizes wastes (over-processing, inventory, waiting, rework, transportation, motion) Reduces variation Increased Efficiency Minimizes Idle time Unbalanced Line High work load in some stages (Overburden) Maximizes wastes (over-processing, inventory, waiting, rework, transportation, motion) High variation in output Restrict one piece flow Maximizes Idle time Poor efficiency

4. Important Terminologies TASK PRECEDENCE : The sequence in which tasks are performed. CYCLE TIME : The time expressed in minutes between two simultaneous products coming off the end of a production line. PRODUCTIVE TIME PER HOUR : The average number of minutes a workstation is working in an hour. WORKSTATION : A physical area where a worker with tools/ one or more machines, or an unattended machines like a robot performs a particular set of task in a production line. WORK CENTER : A small group of identical workstations, where each workstation performs the same set of task. NUMBER OF WORKSTATIONS WORKING : The amount of work done at a work centre expressed in number of workstations. MINIMUM NUMBER OF WORKSTATIONS : The least number of workstation that provides the required production. ACTUAL NUMBER OF WORKSTATIONS : This is the total number of workstations required on the entire production line. It is calculated as the next higher integer of the number of workstations working. UTILIZATION : The percentage of time a production line is working.

5. Incremental Utilisation (IU) Heuristic A heuristic method is a procedure that can find a good feasible solution for a given class of problems, but which is not necessarily an optimal solution. It add tasks to a workstation in a precedence task order. To each task added to the station, operators are added when necessary, and the station utilization is calculated by equation. Tasks are added at the used station until its utilization is 100%, or until a reduction occurs, considering the new task and another operator when necessary. Then, a new station is considered, and the procedure is repeated on the next workstation for the remaining tasks.

6. The incremental utilization heuristic is appropriate when one or more task times is equal to or greater than the cycle time. An important advantage of this heuristic is that it is capable of solving line-balancing problems regardless of the length of task times relative to the cycle time.

7. Example The back room operations of a fast food restaurant have these tasks:

8. If 100 burgers per hour must be prepared by the crew and 50 minutes per hour must be prepared by the crew and 50 minutes per hour are productive: a.Draw a diagram of the precedence relationships. b. Compute the cycle time per burger in minutes. c. Compute the minimum number of workstations required. d. How would you combine tasks into workstations to minimize idle time? Use the incremental utilization heuristic. Evaluate your proposal.

9. Solution a) Compute the cycle time per burger: Cycle time = Productive time/ hour Demand/ hour = 50 minutes/hour 100 burgers/ hour = 0.50 minute/burger b) Compute the minimum number of workstations: Minimum no. = Sum of task times x Demand/hour of workstations Productive time/hour = 5.07 minutes/burger x 100 burgers/hour 50 minutes/hour = 0.14 workstations

10. c) Precedence Diagram

11. d) Evaluation of the proposal: Utilization= Minimum number of workstations Actual number of workstations = 10.14 43 = 0.2358 or 23.58 %

12. Longest-Task-Time Heuristic

13. Stations Task Task Time (in minutes) Number of Following Tasks Remaining Unassigned Time (Balance-Delay) Feasible Remaining Tasks Task with Most Followers Task with Longest Operating Time Station 1 A 12 11 3 IDLE None Station 2 B C D 6 6 2 10 4 4 9 3 1 IDLE C,D,E D,E None C,D,E D,E C D ,E Station 3 E F I 2 12 1 4 3 3 13 1 IDLE F,I, G I None F,I,G F Station 4 G H 7 5 3 2 8 3 IDLE H, J None H, J H Station 5 J K 4 6 2 1 11 5 IDLE K None       Station 6 L 7 8 IDLE None    

14. STEP 7. Evaluate the efficiency of the line balance. EFFICIENCY = (SUM OF ALL TASK TIMES)/(ACTUAL NO OF WORKSTATIONS)X(CYCLE TIME) = (70) / (6) X (15) = 0.778 OR 77. 78 %

15. Cars for the masses Cost $850 Built new plant at Highland Park, Michigan Ford consulted Frederick Taylor, Creator of Scientific Management Installation of Gravity Slides December 1, 1913, the first large scale assembly line was officially launched Assembly Line- The Ford Way

16. Cars 84 Steps in the assembly line Interchangeable parts Less waste and higher quality product Production time dropped from over 12 hours to just 93 mins Produced 3,08,612 cars in 1914 Cost of Model T dropped to $260 in 1924 Work time was reduced from 9 to 8 hours and wages doubled to $5 a day Assembly Line- The Ford Way

17. Apparel Industry With proper implementation of line balancing it was seen that the efficiency was further increased.

18. Benefits of Assembly Line Balancing Technical Benefits Economic Benefits

19. Limitation of Line Balancing Production lines were designed so that conveyor belts paced the speed of the employees work . This arrangement wasn ' t appreciated by the employees . Inevitable changes lead to production lines being out of balance . Rebalancing causes disruptions to production 

20. THANK YOU!