Batch location method

Batches are located in the pipeline using a combination of batch and fragment table data.

Batch records themselves do not provide any location information. They mainly contain general batch characteristics:

• Identifier

• Product

• Total Size

• Density

The fragment records provide the location of the batch.

Fragment records contain information on a specific instance of a batch. A batch can have one or more fragments that belong to it. A fragment record includes:

• The batch that the fragment belongs to.

• The pipe_segment that the fragment is in.

• Size of the fragment.

• The next fragment upstream. This reference is blank if the fragment is the first one in the segment.

• The next fragment downstream. This reference is blank if the fragment is the last one in the segment.

From this information and from size and length information from the pipe_segment record, any information about the fragment location can be derived, including volume offset information for the fragment and linepost location of the head and tail of the fragment. It is this information that provides the information on how to represent the batches in the pipe bar displays and batch tabulars.

Note: A fragment can only be in one segment at a time. When a fragment for a batch reaches the end of a segment and volume from the batch begins to move into the next segment, a new fragment record must be created for the instance of the batch in the next segment.