code: @Override
  	public List<BatchPartitionWorkUnit> buildNewParallelPartitions(PartitionsBuilderConfig config) 
  			throws JobRestartException, JobStartException {
  
  		List<JSLJob> jobModels = config.getJobModels();
  		Properties[] partitionPropertiesArray = config.getPartitionProperties();
  
  		List<BatchPartitionWorkUnit> batchWorkUnits = new ArrayList<BatchPartitionWorkUnit>(jobModels.size());
  
  		int instance = 0;
  		for (JSLJob parallelJob  : jobModels){
  			Properties partitionProps = (partitionPropertiesArray == null) ? null : partitionPropertiesArray[instance];    			
  
  			if (logger.isLoggable(Level.FINER)) {
  				logger.finer("Starting execution for jobModel = " + parallelJob.toString());
  			}
  			RuntimeJobExecution jobExecution = JobExecutionHelper.startPartition(parallelJob, partitionProps);
  			jobExecution.setPartitionInstance(instance);
  
  			if (logger.isLoggable(Level.FINE)) {
  				logger.fine("JobExecution constructed: " + jobExecution);
  			}
  			BatchPartitionWorkUnit batchWork = new BatchPartitionWorkUnit(this, jobExecution, config);
  
  			registerCurrentInstanceAndExecution(jobExecution, batchWork.getController());
  			
  			batchWorkUnits.add(batchWork);
  			instance++;
  		}
  
  		return batchWorkUnits;
  	}
docs: Build a list of batch work units and set them up in STARTING state but don't start them yet.