Start or pause jobs

Note: PEM transactions should not be performed on jobs that are part of an MES process model, as PEM manages its own jobs. Doing so could result in MES process model jobs being overwritten by the PEM transactions.

Because the PEM instance does not have an explicit mechanism for starting/stopping jobs, the jobs created on the fly are started and stopped automatically.

When the identified job is not currently running on an entity, then the job is started on the entity. The entity is nothing, but the parent object hosting this OCO. When no such job positions are available, then the oldest job that is running on this entity will be stopped, and the identified job will be started on this entity. When the identified job is running, the job will be kept running.

Additionally, when a new Job is created, an associated BOM 0 record (job_bom.bom_pos = 0) also gets created along with this job identifying the item being produced by this OCO. The job BOM 0 record will be created using the supplied values and the default values supplied.

If the identified job exists, but the supplied production item is not the same item in the job, then a new job_bom_subst record for this item is created. The purpose of creating job_bom_subst record is to individually maintain various BOM flags such as update_inventory etc. for each Item produced/consumed in a job.

If the supplied item is a consumption item for this job, then a new BOM record is created for the supplied item for this job. The bom_pos number is the next minimum number currently available in the Job_Bom table for the supplied job.

If a consumption transaction is sent to the middleware before the production item is identified, the BOM 0 item is created with the default item configured in the System_Attribute table for attribute Default ItemID. When the actual production transaction is triggered, then the event updates the BOM 0 item and the item produced by the job (job.item_id) with the supplied item.