# Performance evaluation in Jsim

## Assembly Process

## Case Description

Stage | Technology | Input | Output | Duration |

1 | Adhesive joining | Component1, Component2 | WIP1 | Normal(10, 2) |

2 | Spot welding | WIP1, Component3 | WIP2 | Normal(5, 1) |

3 | Hemming | WIP2, Component4 | Final product | Normal(2, 1) |

The assembly process is a combination of three stages: Adhesive joining, Spot welding and hemming. And the Final product is a result of joining the four components: Component 1, Component 2, Component 3 and Component 4 where WIP1 and WIP2 are the intermediary outputs during the process. The table below defines the input, output and processing time of each stage.

But while modelling the system in JMT, we have eliminated the intermediary outputs WIP 1 and WIP 2. Instead we have assumed Final product to travel throughout the assembly process

## Formal Model

## Performance Evaluation

### Modelling of the system

Open **JSIM graph** from the various tools in the home panel of JMT software

Select the

**source and sink**icons in the toolbar and then place it in the workspace

Insert machines into the workspace by clicking the **queue** icon in the toolbar

Insert Fork and joins into the system by clicking on the above highlighted icons. All the 4 components gets divided at **Fork 1** and they are routed accordingly

#### Customer Classes

Click on

**Add class**buttonAll the components are selected as

**open**typeSelect

**fork**as the reference station for the componentsSelect

**source**as the reference station for the final product

Click on

**Edit**button and select**Exponential**in order to record the interarrival time of final productEnter the desired generation rate which is

**1 part/second**

#### Fork 1

Select

**Infinite**capacity option under the queue section of Fork 1

Select

**Branch probabilities**as the fork strategy for Component 1Enter the probability as 1 for

**Join 1**and 0 for other two joins

Select

**Branch probabilities**as the fork strategy for Component 2Enter the probability as 1 for

**Join 1**and 0 for other two joins.

Select

**Branch probabilities**as the fork strategy for Component 3Enter the probability as 1 for

**Join 2**and 0 for other two joins

Select

**Branch probabilities**as the fork strategy for Component 4Enter the probability as 1 for

**Join 3**and 0 for other two joins

Select

**Multi Branch Class Switch**as the fork strategy Final product. Here the final product is modelled throughout the process eliminating the intermediary outputs WIP 1 and WIP 2

#### Join 1

Select

**Standard join**as the join strategy for all the componentsSelect

**Quorum**as the join strategy for the Final product. Follow the same for all the joins

Select

**Disabled**option as the routing strategy for the components 3 and 4Select

**Probabilities**as routing strategy for the Final productEnter the probability as 1 for

**Adhesive joining**

#### Adhesive joining

Select

**Infinite**capacity option under the queue section of Adhesive joining

Select

**Disabled**as the strategy for all the components under Service time distributions tableSelect

**Load independent**as the strategy for Final product and click EditChoose

**Normal**distributionEnter 10 as the mean and 2 as the standard deviation value

Select

**Random**option as the routing strategy for the componentsSelect

**Probabilities**as routing strategy for the Final productEnter the probability as 1 for

**Join 2**

#### Join 2

Select

**Disabled**option as the routing strategy for the components 1,2 and 4Select

**Probabilities**as routing strategy for the Final productEnter the probability as 1 for

**Spot welding**

#### Spot welding

Select

**Disabled**as the strategy for the componentsSelect

**Load Independent**as the strategy for Final product. Enter normal(5,1) as the service time

Select

**Probabilities**as routing strategy for the Final product and**Random**for the componentsEnter the probability as 1 for

**Join 3**

#### Join 3

Select

**Disabled**option as the routing strategy for the components 1,2 and 3Select

**Probabilities**as routing strategy for the Final productEnter the probability as 1 for

**Hemming**

#### Hemming

Select

**Disabled**as the strategy for the componentsSelect

**Load Independent**as the strategy for Final product. Select normal distribution and enter 2 as mean and 1 as standard deviation

Select

**Probabilities**as routing strategy for the Final product and**Random**for the componentsEnter the probability as 1 for

**Sink**

#### Performance Indices

Click on

**Select an index**drop down box and choose Throughput per sink and Utilization as indicesSelect

**Final product**as the class and**Sink**as the stationSelect all the three stations in order to find the utilization

### Simulation results

Utilization of :

Adhesive joining = 1

Spot welding = 1

Hemming = 1

Throughput of the system = 0.4851

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