Business processes frequently need concurrent processes such as different processes performed in different departments related to some or all of the same documents at the same time – The use of separate Processes with links and locks for shared documents accomplishes it and allows for concurrency.
There is also a need for tasks within the same process to operate concurrently (i.e., in Parallel) on the same work item – In other words, at the same time. When there is no dependency (i.e., required sequential order) for separate paths, except that they all must be done at some point in the process, the AND-Split and Merge Tasks can be used to get more of the work going at the same time and faster.
To illustrate parallel tasks, consider the following Retirement Application Process where an applicant submits his application form for his company retirement pension benefits that includes their eligibility for Social Security Benefits as well as to obtain additional information by mail/email from the applicant such as their IRS Withholding preferences.
The following process flow diagram (shown below) is a Swim-Lane Process Diagram where each of the swim lanes represents independent activities performed by different groups or departments.
Notice that after a Retirement Application form has been received and indexed by the Retirement Claims Processing department, someone in that department verifies that the Applicant is a Member of the company Pension Fund and has the right to apply for benefits.
If they are not a member, the Problems & Resolutions group responds to the applicant that they are ineligible for retirement/pension benefits.
However if the Verify step results in a Yes, the Application Form can be processed In-Parallel by three groups, the: Retirement Claims Processing, SSA Transcripts and IRS Withholding Options (i.e., the Parallel Split Point). Once all three of these Parallel Tasks (shown above) have completed (i.e., the Parallel Merge Point) the remaining processing for the Retirement Application can be done by the Retirement claims Processing group.
The AND Split and Merge Tasks are progression building blocks that work together to handle the splitting out from one path into separate parallel paths and their eventual convergence of the parallel paths back into one common path. This example will be used in the following AND Split and Merge sections.
