Performance evaluation of a Flow Shop using Jsim

The flow shop is composed by 4 machines and 4 buffers connected . The processing time of each machine depends on the part (class) to be worked. The sizes of the buffers are reported in Table.

The failure and repair probabilities for each machine, considering two different failure modalities, are reported in Table

buffer capacity

failure and repair time

The systems includes 4 different machine type and 4 buffers located upstream of the system and between the machines

Consider the production of 3 parts (classes), whose production processes are reported in Table. In the case of open system, the generation rate is reported in Table

Flow Shop

process time

Formal Representation

formal model

Performance Evaluation

home-panel

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

new

1. click ‘file’

2. open new file

create-machines

1. Insert machines into the workspace by clicking the queue icon in the toolbar

2. Insert machine-1,2,3,4

source

1. Select the source icon in the toolbar

2. place it in the workspace

sink

1. Select the sink icons in the toolbar

2. Place it in the workspace

connection

1. Click on the connect stations icon and then connect all the stations with regard to the case

2. Clicking on this icon optimizes the layout

define_customer_class

1. Click ‘Define Customer Class’ icon

2. Click on the Add class button in order to the add the parts

3. Write part name.

4. Select open in type option

5. Select the source

Note:Follow the same steps for Part-A and Part-B

define_class-2

1. Click on the edit button under interarrival time distribution

2. Select Exponential distribution

3. Enter the generation rate of each part

Note:Follow the same steps for Part-A and Part-B

edit_m1

1. Double click on queue-1

2. Modify the station name as B1-M1

3. Select finite under the capacity and then enter the value of buffer level+1 (11) in max no. customers box

Note:Follow the same steps for Queue-2,Queue-3,Queue-4

edit_m1.2

1. Click on Service Section

2. Enter number of machines

3. Click on Edit

Note:Follow the same steps for Queue-2,Queue-3,Queue-4

edit_m1.3

1. Select the deterministic distribution

2. Enter the process time value of the part with respect to the machine M1

3. Click OK

Note:Follow the same steps for Queue-2,Queue-3,Queue-4

edit_m1.4

1. Select Routing Section

2. Select Random as the routing strategy for part A in the routing section of the station

3. Define the strategy as random for M2 and for M3

Note:Follow the same steps for Queue-2,Queue-3,Queue-4

indices

1. Click on ‘Define Performance Indices’

2. Click on Select an index option and select Throughput and Utilization

3. Select Class of each indices

4. Select Systems of each indices

5. Click on ‘Static-Resolution

6. Click ‘Done’

run_simulation

1. Run the Simulation

throughput

Throughput of:

Part A=0.0832

Part B=0.0991

Part C=0.1631

utilisation-1

Utilization of:

M1=1

M2=1

M3=1

M4=0.7908

utilisation-2