how to create SLA for incident management.

Dear All,

I am new to the service manager and going through the POC of a tool in which I need to create an SLA for incident management. Can anyone guide me on how to create an SLA which would help me to attain an objective of 

1. If a priority 1 incident is raised an SLA should be applied to it stating 25 %. 50%  and SLA breach

I have already created an SLA and SLT under process target tab of SLA but when I raise an incident there is no SLA shown in the process tab.

Can anyone help me on this.

Thanking you in advance.

Note: Please refer to screenshot for better understanding

Regards

Harsh Vardhan