| Software (SW) Inspections (Formal Inspections or | | | | processes we use to conduct them. These processes |
| Peer Reviews) have been used for decades to | | | | are our retrospective understanding of how |
| remove defects during SW development from | | | | inspections were successfully conducted in the past. |
| requirements, design, code, test, or documentation | | | | Unfortunately, they rarely convey the manner (discipline |
| artifacts. Several years ago, I was attempting to | | | | and attention to detail) with which those inspections |
| quantify effectiveness (Return on Investment) for SW | | | | were conducted. They typically suggest, for example, |
| Inspections, in other words, how many need to be | | | | inspecting less than 400 lines of new code in a single |
| conducted, and how well, to achieve quality and cost | | | | inspection. Now, one commonly sees engineers |
| goals. I searched the internet but found nothing useful. | | | | relaxing this guidance by inspecting much larger code |
| After developing a solution, I was troubled by the lack | | | | sizes. That's the rub. Using a proven process doesn't |
| of other solutions on the internet. Why hadn't a solution | | | | guarantee that it will be executed with the same |
| been found? | | | | effectiveness as the pioneers who developed it. |
| If brilliant minds had failed at this then my solution was | | | | 3. "...Handicap of authoritative... people" |
| likely a joke! I was relieved to find that companies | | | | The issue with authoritative people (experts) is that we |
| apparently weren't trying to find a solution. They didn't | | | | often place too much faith in the validity or applicability |
| question SW Inspection effectiveness, so there was | | | | of their opinions. The problem here for SW Inspections |
| no pressing need to quantify it. But why would they | | | | is over-reliance on expert approved processes. |
| assume that SW Inspections are effective? | | | | Experts may have approved a SW Inspection |
| I was pleased to find an answer in Nassim Taleb's | | | | process, but that doesn't mean that a company is |
| prescient book, The Black Swan -- The Impact of the | | | | effectively using it. |
| Highly Improbable. His concept, the Triplet of Opacity, | | | | Summary |
| asserted that we often make assumptions about the | | | | Some of us (in the SW Industry) haven't quantified the |
| past and then falsely rely on those assumptions. As | | | | effectiveness of SW Inspections because, through no |
| explained below, his concept applies to SW Inspections | | | | fault of our own, we have taken them for granted. |
| and even Coconut Cream Pie! Quotations are from his | | | | This may be the result of the natural human reactions |
| book. | | | | identified here: our understanding of how they work, |
| Taleb: "The human mind suffers from three ailments | | | | how to conduct them, or the supposed credibility of the |
| as it comes into contact with history, what I call the | | | | processes we use. |
| triplet of opacity": | | | | As an analogy of how easily this occurs, consider the |
| 1. "The Illusion of Understanding" | | | | following true story. I love Coconut Cream Pie so |
| This is the tendency to view the world as more | | | | decided to try the recipe used by my wife's aunt. The |
| "understandable, more explainable, and therefore more | | | | Triplet of Opacity nailed me: 1) I thought it would be |
| predictable than it actually is". We typically, for example, | | | | straightforward but it wasn't; 2) she sent me her recipe |
| assign simple causes for business failings or | | | | but gave me more credit for cooking skill than I |
| successes that actually stemmed from complex | | | | deserve; and 3) she had a reputation for her pies so I |
| situations. In the same way, some users have | | | | brashly make enough for 2 pies! |
| mistakenly felt that they understood SW Inspection | | | | The filling was a disgusting brown and tasted like |
| effectiveness because of their core function: removing | | | | burned caramel pudding! |
| defects so they don't escape into formal test. This is a | | | | In summary, due to human nature and the passage of |
| component of inspection effectiveness, but is, | | | | time, some companies may experience less SW |
| unfortunately, just one of the factors that influence | | | | Inspection effectiveness than they've assumed. Taking |
| effectiveness. | | | | action to measure and improve inspection |
| 2. "Retrospective Distortion" | | | | effectiveness may provide significant leverage in |
| Our perception of a historical event is naturally more | | | | meeting the quality and cost demands of today's |
| simplified and organized than what actually happened. | | | | marketplace. |
| For SW Inspections, this distortion relates to the | | | | |