Types of Job Sequencing:

First Come First Serve (FCFS)

Jobs are processed on the basis of their arrival in the shop-floor.

Shortest Processing Time (SPT)

Jobs are processed according to their processing time. Job having the least processing needs is processed first.

Earliest Due Date (EDD)

Jobs are sequenced on the basis of their due dates needs where, the job having least due date is processed first, followed by others.

Slack Time Remaining (STR)

Slack time is described as within the due date of the job minus the processing time remaining. The job having the least slack time remaining will be processed first.

Last Come First Serve (LCFS)

According to this sequencing rule, the jobs that came later on in the shop floor are placed on the top, while the previously arrived jobs shifted towards the bottom. The processing is done on the similar basis.

Critical Ratio (CR)

Critical ratio is attained by subtracting the current time of the job by its due date and further divided by the numbers of working days remaining. The job with the lowest critical ratio is processed first.

Random Order (RO)

In this kind of sequencing, jobs are selected randomly for the processing.

Queue Ratio (QR)

It is attained by dividing the slack time remaining of the job by the planned remaining queue time. The jobs having the lower queue ratio are preferred first for the processing.

Start Time (ST)

It is attained by subtracting the lead time of the job by its due date. The job having the earliest start time is processed first.

Longest Processing Time (LPT)

The jobs are arranged according to their processing times and the job with the longest processing time is processed first.

Slack Time Remaining per Operation (STRPO)

It is computed by the following formula :

STRPO = (Time Remaining before Due Dates - Remaining Processing Time) /Number of  Remaining Operations

Jobs having the shortest STRPO are processed first.