5th Edition PMBOK Guide–Chapter 8: Perform Quality Assurance vs. Perform Quality Control


1.   Introduction

The last posts covered the inputs and outputs, as well as some of the tools & techniques of the first quality-related  process, 8.1 Plan Quality.   I was planning on going on to the second quality-related process, 8.2 Perform Quality Assurance, but then it occurred to me that I ought to do an overview of the difference between that second process and the third one, 8.3 Perform Quality Control.

In managing study groups for now two groups of students studying for the CAPM and PMP, the difference between these two processes seems to be a little unclear to many encountering it for the first time.   The reason why is that Assuring Quality and Controlling Quality seem to have the same end in mind, that is, to make sure the quality of the product or project matches what was set forth in Plan Quality, isn’t that right?   Well, the end is the same, but the focus is different.   This post will try to explain why using an analogy to baking.

2.  Quality Assurance vs. Quality Control

The first process is in the planning process group, which should be obvious from the name.   However, the word “perform” sometimes throws people off when it comes to categorizing the other two.   Perform Quality Assurance is actually in the executing process group, and Perform Quality Control is in the monitoring & controlling process group.   The reason is that quality assurance focuses on the work being done; it is being done according to the processes set forth in the Quality Management Plan?   Quality control focuses on the actual deliverables that are a product of that work, to see if they meet the level of quality in the Quality Management Plan.

I have a cookbook which provides me with a source of new recipes if I get bored with making the same old thing.   Many times the recipes work out great, but sometimes … they don’t.    I tried to make chocolate brownies from a low-fat recipe and I couldn’t figure why they came out more gooey than chewy, to put it bluntly.

At this point, I had to analyze, was it a problem with a) the ingredients, b) the recipe, or c) the equipment?    Analyzing whether I followed the steps of the recipe was an example of quality assurance.   Did I omit any steps that the recipe called for?   I couldn’t find any–at first.

Then I went to the ingredients, and tried to see if I skipped any, or added the wrong amount of any of them.   This would be more along the lines of quality control.   Nope, that wasn’t it.    The brownies tasted just fine, but the texture was off.  The final product didn’t seem like it got enough heat, and so was underdone somehow.   That’s when I figured it out–the pan was supposed to be on the middle rack, and I put it on the top rack, so it wasn’t getting the heat it required.

I did a design of experiments, and decided to make another batch with the rack in the middle, like the recipe book actually called for.   Success!   So it was not a problem with the ingredients or the equipment, but the processes I followed, in fact, the very last one of putting it in the oven in the wrong spot.   But this shows you that the focus can be on the processes or the product to find out where a quality problem is.   If you do the processes wrong, or the raw materials do not fit the specifications, or there is a problem with the equipment–any of these things can cause the product to not exhibit the quality that was specified in the quality management plan.   Although they are separate project management processes, they can be done in tandem, although in a company it is usually a quality audit team that sees if the processes are being followed in order to fulfill 8.2 Perform Quality Assurance, whereas the quality control team sees if the product is coming out as it should if the processes are being followed faithfully, in order to fulfill 8.3 Perform Quality Control.

I hope this analogy gives you a feel for the difference between the two–they have the same overall purpose, to ensure good quality in the product, but they have different focuses and that is why they are considered two separate processes.

Having made this distinction a little clearer (I hope), the next post will discuss the inputs and outputs, as well as the tools & techniques of 8.2 Perform Quality Assurance.

2 Responses

  1. Well done. This has been a murky area for me, and drawing hard lines between the “Assurance” and “Control” processes has not made any sense thus far. This did. Thanks.

  2. I actually could state the difference between the two but it still seems to me that whether you are monitoring the process or the deliverable you are still monitoring so I can’t figure out why this would be an execution process.

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