In solving 2 machine and n jobs sequencing problem, the following assumption is wrong

Options

A. No passing is allowed
B. Processing times are known
C. Handling time is negligible
D. The time of passing depends on the order of machining.

Answer

To solve the problem regarding the assumptions in the two-machine and n-jobs sequencing problem, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understanding the Problem**: We need to identify which of the given assumptions is incorrect in the context of a two-machine and n-jobs sequencing problem.

2. **Analyzing Each Option**:
- **Option 1: No passing is allowed**: This assumption states that once a job is started on a machine, it cannot be interrupted or passed to another machine until it is completed. This is a correct assumption in the context of many sequencing problems, as passing can complicate the scheduling.
- **Option 2: Processing times are known**: This assumption indicates that the time required for each job on each machine is known beforehand. This is a standard assumption in sequencing problems, making it correct.
- **Option 3: Handling time is negligible**: This assumption suggests that the time taken to move jobs between machines is so small that it can be ignored. This is often assumed in theoretical models, making it a correct assumption.
- **Option 4: The time of passing depends on the order of machining**: This assumption implies that the time taken to pass jobs from one machine to another varies based on the sequence in which jobs are processed. In many standard sequencing problems, this is not true, as passing time is usually considered constant or negligible.

3. **Identifying the Incorrect Assumption**:
- After analyzing all options, we find that **Option 4** is the incorrect assumption. In a typical two-machine and n-jobs sequencing problem, the time of passing does not depend on the order of machining.

### Conclusion:
The incorrect assumption in solving the two-machine and n-jobs sequencing problem is **Option 4: The time of passing depends on the order of machining**.

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