Chapter 1.7: Process Spaghetti

With paper reduced, people are the most visible component of any process.  Not only are they easy to spot, but in many information intensive organizations they are the most expensive resource.  When it comes to improving processes, this makes people, and the work they do, targets for scrutiny.  One of the unwritten laws associated with any expensive resource is that it must be busy all of the time. 

Suppose somebody in an organization is not busy.  What happens?  They are given more work to do.  They may be given work that is part of their current process, or it may be work from another unrelated process.  What probably wouldn’t happen is an analysis of why their current activities did not keep them busy.   

Because of their roots in paper, the activities of most information processes are performed in a serial order.  Each activity is executed one-at-a –time and the next not started until the prior is completed.  Since paper was expensive to copy, parallel processes were rarely used.  Because of the process rings-of-a-tree phenomenon, the serial process flow model is still prevalent even after paper is eliminated. 

A natural characteristic of any serial process is that it creates bottlenecks.  An example of this is a highway.  Where one section of a highway can be smooth sailing, the next section can be stop-and-go, followed by a section where traffic is again flowing freely. 

A bottleneck in a serial process slows the amount of work getting through just like a bottleneck in a highway.  If work starts to pile up behind a bottleneck, the people downstream of the bottleneck will soon run out of things to do.  Then what happens?  They are given more work to do. 

Another characteristic of a serial process is that bottlenecks can independently move up and down a process.  Watch the bottlenecks of a highway and you’ll notice that some bottlenecks always occur at the same location while other bottlenecks appear to move randomly up and down the highway. 

The same occurs for serial information processes.  One day a bottleneck could be located at one activity in a process; and the next day at another.  Bottleneck locations change as the mix of work and the available resources change.  If a bottleneck moves, people with plenty of work to do, may suddenly not have enough.  Then what happens?  They are given more work to do.  

As bottlenecks shift from one location to the next, the cycle of handing out more work to keep people busy continues.  If a bottleneck is temporarily removed so that someone downstream now becomes too busy, nothing is usually done other than to ask them to work harder.  But the bottleneck moves again so that the same person now has too little to do, they are given more work. 

Finally, the ongoing effort to make sure everyone is busy results in a status quo where everyone always has too much to do.  This status quo is called process spaghetti. 

Figure 1.10 is a depiction of the bottleneck principle of process spaghetti.  Process A, B, and C are each serial processes.  Each box indicates one or more activities executed by one or more people.  The first activity of each process is numbered A-1, B-1, C-1; the second A-2, B-2, C-2, etc.  Note that the same people are responsible for executing the activities of A-2, B-2, and C‑2.  In this example these people originally only had activity B-2 to perform.  But over time they were given the work of A-2 and C-2 to keep them busy.

Figure 1.10:  Process Spaghetti and the Bottleneck Principle

 

People downstream of a bottleneck are given more work to stay busy until they too become a bottleneck.  This principle applies until all process activities are bottlenecked. 

As process spaghetti begins to develop it causes even more spaghetti.  Suppose the people responsible for activities A-4 and B-3 were only recently given activity A-4 because of a bottleneck at activity B-2.  Since it’s a new activity for them they want to make sure it’s done well, so they decide to do all of the A-4 work before any B-3 work.   

Now under this scenario, the people responsible for activity B-4 no longer has enough to do, because B-3 is now bottlenecked.  Then what happens?  They are given more work to do. 

Process spaghetti once formed is very difficult to unravel.  Suppose there was an effort to remove the bottlenecks from Process B in Figure 1.10.  If the people responsible for activities A-2, B-2, and C-2 were told to prioritize B-2 work over everything else, then a logjam of work would suddenly flow to B-3.  The size of the bottleneck for the people responsible for A-4 and B-3 would increase.  In addition, work flowing to A-3 and C-3 would be reduced further; bottlenecking those processes.  The net result of removing the B-2 bottleneck could be a reduction in the value created by all three processes. 

A lot of progress can be made removing bottlenecks before anyone notices a change in created value.  It can take months to clear a single process of its bottlenecks without impacting too negatively otherwise seemingly unrelated processes.   

The time and cost it takes to unwind process spaghetti is not the only issue.  It can also be difficult to sustain management commitment.  Bottleneck removal projects can quickly run out of steam when management runs out of patience waiting for a positive result from a Process B; while hearing about all the problems cropping up with Processes A and C.