Advertisements
Advertisements
प्रश्न
A toy manufacturing company produces five types of toys. Each toy has to go through three machines A, B, C in the order ABC. The time required in hours for each process is given in the following table.
| Type | 1 | 2 | 3 | 4 | 5 |
| Machine A | 16 | 20 | 12 | 14 | 22 |
| Machine B | 10 | 12 | 4 | 6 | 8 |
| Machine C | 8 | 18 | 16 | 12 | 10 |
Solve the problem for minimizing the total elapsed time.
A toy manufacturing company produces five types of toys. Each toy has to go through three machines A, B, C in the order ABC. The time required in hours for each process is given in the following table.
| Type | 1 | 2 | 3 | 4 | 5 |
| Machine A | 16 | 20 | 12 | 14 | 22 |
| Machine B | 10 | 12 | 4 | 6 | 8 |
| Machine C | 8 | 18 | 16 | 12 | 10 |
Find the total elapsed time and also find idle time for machine B.
उत्तर
| Type | 1 | 2 | 3 | 4 | 5 |
| Machine A | 16 | 20 | 12 | 14 | 22 |
| Machine B | 10 | 12 | 4 | 6 | 8 |
| Machine C | 8 | 18 | 16 | 12 | 10 |
Here min A = 12, max B = 12, min C = 8.
Since min A ≥ max B is satisfied, the problem can be converted into a two-machine problem.
Let G and H be two fictitious machines such that G = A + B and H = B + C
Then the problem can be written as
| Type | 1 | 2 | 3 | 4 | 5 |
| Machine G | 26 | 32 | 16 | 20 | 30 |
| Machine H | 18 | 30 | 20 | 18 | 18 |
Using the optimal sequence algorithm, any one is an optimal sequence that can be obtained.
| 3 | 2 | 5 | 4 | 1 | |
| or | 3 | 2 | 5 | 1 | 4 |
| or | 3 | 2 | 4 | 5 | 1 |
| or | 3 | 2 | 4 | 1 | 5 |
| or | 3 | 2 | 1 | 4 | 5 |
| or | 3 | 2 | 1 | 5 | 4 |
| Type | Machine A | Machine B | Machine C | |||
| 3 | 0 | 12 | 12 | 16 | 16 | 32 |
| 2 | 12 | 32 | 32 | 44 | 44 | 62 |
| 5 | 32 | 54 | 54 | 62 | 62 | 72 |
| 4 | 54 | 68 | 68 | 74 | 74 | 86 |
| 1 | 68 | 84 | 84 | 94 | 94 | 102 |
∴ Total elapsed time = 102 hrs.
Idle time for machine A = 102 – 84 = 18 hrs
Idle time for machine B = (102 – 94) + 54 = 62 hrs
Idle time for machine C = 16 + 12 + 2 + 8 = 38 hrs.
Notes
Students can refer to the provided solution According to their question.
APPEARS IN
संबंधित प्रश्न
A machine operator has to perform two operations, turning and threading on 6 different jobs. The time required to perform these operations (in minutes) for each job is known. Determine the order in which the jobs should be processed in order to minimize the total time required to complete all the jobs. Also find the total processing time and idle times for turning and threading operations.
| Job | 1 | 2 | 3 | 4 | 5 | 6 |
| Time of turning | 3 | 12 | 5 | 2 | 9 | 11 |
| Time for threading | 8 | 10 | 9 | 6 | 3 | 1 |
A company has three jobs on hand. Each of these must be processed through two departments, in the order AB where
Department A: Press shop and
Department B: Finishing
The table below gives the number of days required by each job in each department
| Job | I | II | III |
| Department A | 8 | 6 | 5 |
| Department B | 8 | 3 | 4 |
Find the sequence in which the three jobs should be processed so as to take minimum time to finish all the three jobs. Also find idle time for both the departments.
An insurance company receives three types of policy application bundles daily from its head office for data entry and tiling. The time (in minutes) required for each type for these two operations is given in the following table:
| Policy | 1 | 2 | 3 |
| Data Entry | 90 | 120 | 180 |
| Filing | 140 | 110 | 100 |
Find the sequence that minimizes the total time required to complete the entire task.
Find the optimal sequence that minimizes total time required to complete the following jobs in the order ABC. The processing times are given in hours.
| Jobs | I | II | III | IV | V | VI | VII |
| Machine A | 6 | 7 | 5 | 11 | 6 | 7 | 12 |
| Machine B | 4 | 3 | 2 | 5 | 1 | 5 | 3 |
| Machine C | 3 | 8 | 7 | 4 | 9 | 8 | 7 |
If there are n jobs and m machines, then there will be_______ sequences of doing the jobs.
Choose the correct alternative :
In solving 2 machine and n jobs sequencing problem, the following assumption is wrong
Choose the correct alternative :
In a 3 machine and 5 jobs problem, the least of processing times on machine A, B and C are 5, 1 and 3 hours and the highest processing times are 9, 5 and 7 respectively, then it can be converted to a 2 machine problem if order of the machines is:
Fill in the blank :
The time for which a machine j does not have a job to process to the start of job is called _______.
State whether the following is True or False :
If there are two least processing times for machine A and machine B, priority is given for the processing time which has lowest time of the adjacent machine.
State whether the following is True or False :
In a sequencing problem, a machine can process more than one job at a time.
State whether the following is True or False :
The time involved in moving a job from one machine to another is negligibly small.
Solve the following problem :
Five jobs must pass through a lathe and a surface grinder, in that order. The processing times in hours are shown below. Determine the optimal sequence of the jobs. Also find the idle time of each machine.
| Job | I | II | III | IV | V |
| Lathe | 4 | 1 | 5 | 2 | 5 |
| Surface grinder | 3 | 2 | 4 | 3 | 6 |
Solve the following problem :
Find the sequence that minimizes the total elapsed time to complete the following jobs. Each job is processed in order AB.
| Machines | Jobs (Processing times in minutes) | ||||||
| I | II | III | IV | V | VI | VII | |
| Machine A | 12 | 6 | 5 | 11 | 5 | 7 | 6 |
| Machine B | 7 | 8 | 9 | 4 | 7 | 8 | 3 |
Determine the sequence for the jobs so as to minimize the processing time. Find the total elapsed time and the idle times for both the machines.
Solve the following problem :
A foreman wants to process 4 different jobs on three machines: a shaping machine, a drilling machine and a tapping machine, the sequence of operations being shaping-drilling-tapping. Decide the optimal sequence for the four jobs to minimize the total elapsed time. Also find the total elapsed time and the idle time for every machine.
| Job | Shaping (Minutes) | Drilling (Minutes) | Trapping (Minutes) |
| 1 | 13 | 3 | 18 |
| 2 | 18 | 8 | 4 |
| 3 | 8 | 6 | 13 |
| 4 | 23 | 6 | 8 |
Choose the correct alternative:
| Machine | Job | |||
| A | B | C | D | |
| I | 5 | 6 | 8 | 4 |
| II | 4 | 7 | 9 | 10 |
The optimal sequence for above data is
Choose the correct alternative:
If there are 3 machines A, B and C, conditions for reducing a 3 machine problem to a 2 machine problem with respect to minimum processing time is ______
If there are n jobs and m machines, then there will be _______ sequence of doing jobs.
Choose the correct alternative:
In solving 2 machine and n jobs sequencing problem, the following assumption is wrong
In assignment problem each worker or machine is ______ capable of handling any job
______ time is the time when the machine is available but is waiting for a job to be processed
In sequencing problem the time required to transfer a job from one machine to another is ______
State whether the following statement is True or False:
The Total Elapsed is the time required to complete all the jobs i.e. entire task
State whether the following statement is True or False:
The idle time for a machine is the when machine is available but is not waiting for any job to be processed
State whether the following statement is True or False:
In sequencing problem each machine is of different type
Find the sequence that minimizes total elapsed time to complete the following jobs in the order XY. Find the total elasped time and idle times for each machine.
| Jobs | A | B | C | D | E |
| Machine X | 10 | 2 | 18 | 6 | 20 |
| Machine Y | 4 | 12 | 14 | 16 | 8 |
