Underestimation is Underestimated (a.k.a. Overestimation is Overestimated)

Sometimes it seems like we have an underestimation gene embedded really deep in our cognition but for some “obvious” reason (e.g. underestimation! :) most manager will rather “fight” overestimation and *not* underestimation.

Disclaimer: I have originally estimated this post will take ~33 min but it took me ~240% more time… (this is why I prefer to tweet lately ;)

Six annoying facts about our (/homo sapiens) planning or estimation “skills”:

• We are basically optimistic and have strong desire to please
• We tend to have incomplete recall of previous experience
• We tend to have focus bias when estimating e.g. estimating only the coding phase estimations which is only ~14-37% of the required work
• We tend to postpone what we can a.k.a. “The Student Syndrome”  (Eliyahu M. Goldratt, Critical Chain)
• “It always takes longer than you expect, even when you take into account Hofstadter’s Law” (Douglas Hofstadter, Godel, Escher, Bach: An Eternal Golden Braid)
• We tend to underestimate task completion times – a.k.a. The planning fallacy

Overestimation is Overestimated

“The developers say that this project will take 6 months… I think there’s some padding in their estimates and some fat that can be squeezed out of them…we also need to instill a sense of urgency in the development team… so I’m going to insist on a 3-month schedule. I don’t really believe the project can be completed in 3 months, but that’s what I’m going to present to the developers. If I’m right, the developers might deliver in 4 or 5 months. Worst case, the developers will deliver in the 6 months they originally estimated” (Does this ring *any* bell???)

Four reasons on managers tendency to “fight” overestimations:

• Underestimation (see above :) | “The feature estimation seems bloated” | “Isn’t it 20 min work?” | “Just add another index to the %$^&ing table?” | “It is only one more button…”
• Unreasonable time constraint | “We need this feature yesterday” | “Nothing is impossible for the man who doesn’t have to do it himself” (A. H. Weiler)
• True belief that Parkinson’s “Law” is really a law – “Work expands so as to fill the time available for its completion”
• “The Student Syndrome”  (see above)

So… if feature estimation seems bloated, managers and other project stakeholders fear that Parkinson’s Law and the Student Syndrome would kick in and therefore consciously squeeze the estimates to try to control it (a.k.a. “The Parkinson’s Squeeze”) and when we squeeze where it isn’t needed or was squeezed already, it immediately lead to… UNDERESTIMATION (!!!)

Underestimation is Underestimated

Underestimation creates numerous problems – some obvious, some not so obvious.

• Reduced effectiveness of project plans – Low estimates undermine effective planning by feeding bad assumptions into plans for specific activities. They can cause planning errors in the team size, such as planning to use a team that’s smaller than it should be. They can undermine the ability to coordinate among groups – if the groups aren’t ready when they said they would be, other groups won’t be able to integrate with their work. If the estimation errors caused the plans to be off by only 5% or 10%, those errors wouldn’t cause any significant problems but numerous studies have found that software estimates are often inaccurate by 100% or more (see above). When the planning assumptions are wrong by this magnitude, the average project’s plans are based on assumptions that are so far off that the plans are virtually useless.
• Statistically reduced chance of on-time completion – Developers typically estimate 20% to 30% lower than their actual effort. Merely using their normal estimates makes the project plans optimistic. Reducing their estimates even further simply reduces the chances of on-time completion even more.
• Poor technical foundation leads to worse-than-nominal results. A low estimate can cause you to spend too little time on upstream activities such as requirements and design. If you don’t put enough focus on requirements and design, you’ll get to redo your requirements and redo your design later in the project – at greater cost than if you’d done those activities well in the first place. This ultimately makes your project take much longer than it would have taken with an accurate estimate.
• Destructive late-project dynamics make the project worse than nominal Once a project gets into “late” status, project teams engage in numerous activities that they don’t need to engage in during an “on-time” project… below are some examples when the important characteristic of each of these activities is that they don’t need to occur at all when a project is meeting its goals, these extra activities drain time away from productive work on the project and make it take longer than it would if it were estimated and planned accurately
  • More status meetings with upper management to discuss how to get the project back on track
  • Frequent re-estimation, late in the project, to determine just when the project will be completed.
  • Apologizing to key customers for missing delivery dates (including attending meetings with those customers).
  • Preparing interim releases to support customer demos, trade shows, and so on. If the software were ready on time, the software itself could be used, and no interim release would be necessary.
  • More discussions about which requirements absolutely must be added because the project has been underway so long.
  • Fixing problems arising from quick and dirty workarounds that were implemented earlier in response to the schedule pressure.

Tip of the day
Never intentionally underestimate. The penalty for underestimation is more severe than the penalty for overestimation. Address concerns about overestimation through control, tracking and *mentoring* but not by bias.

****************************************

More related posts (a.k.a. people who read this post also read these posts)

• Software projects anxiety
• The Stockdale Paradox the Pessimistic Developer paradigm
• In Broken Images
• The Dunning Kruger Effect
• The Cone of Uncertainty in Pastel

Justin Kruger & David Dunning have tested and verified the following predictions:

• Incompetent individuals tend to overestimate their own ability and performance 
• Incompetent individuals fail to recognize genuine skill in others (it takes one to know one ;)
• Incompetent individuals fail to recognize the extremity of their inadequacy (“One puzzling aspect of our results is how the incompetent fail, through life experience, to learn that they are unskilled”)
• If they can be trained to substantially improve their own skill level, these individuals can recognize and acknowledge their own previous lack of skill (There is still some hope)

Do you have the confidence that this post isn’t about you? 

Think again… (!!!) - “ignorance more frequently begets confidence than does knowledge” (Charles Darwin)

Do you think this post is about you?

Might be considered vain but interesting enough, the same research have shown that the top performers tended to underestimate their own performance compared to their peers (see chart below). 

So… if you find this post boring, obscure, stupid, annoying, poorly written or inappropriate than please keep in mind it isn’t something I have committed knowingly.

2019-1972=47 (!!!)

Someone wise once gave this as a metaphorical example for a common engineers disorder, he called experience-anxiety-disorder, claiming that NASA stopped sending manned missions to the moon since they now know much more about the complexity and risk with doing this.

During the early seventies, it was a nice, naive working implementation but when NASA engineers started thinking about the next release they have built a five-decades-project-plan simply because they considered all the technological experience they have gained into large complexity buffers.

The Moral Lesson
Keep-it-simple can-do-approach and don’t over-complicate things with the long-tail-little-details when not needed or the project will take 5 decades to finish.

How do you know you are have an experience-anxiety-disorder?
If someone ask you to add a button to change the database schema and this make you feel a mixture of fear, apprehension, heart palpitations, nausea, chest pain, shortness of breath and headache.

What to do?
Sit down and relax, drink a cup of water and then add the damn button!

Last Long-Tail-Detail
Well… I don’t want to ruin this lovely moral lesson with the long-tail-little-detail but the real facts behind this 47 years gap were politics and money (as always) and not that NASA engineers got a severe experience-anxiety-disorder.

Google Trends (a.k.a. my experiment – part IV – Almost forgot…)

• Betty Casey
  
• Most Haunted Life
  
• Piercing & Tattoos
  
• Madonna
  
• World War III (…)
  

“We have all some experience of a feeling, that comes over us occasionally, of what we are saying and doing having been said and done before, in a remote time – of our having been surrounded, dim ages ago, by the same faces, objects, and circumstances – of our knowing perfectly what will be said next, as if we suddenly remember it!” - Charles Dickens

In recent years, déjà vu has been subjected to serious psychological and neurophysiological research. The most likely explanation of déjà vu is that it is not an act of “precognition” or “prophecy”, but rather an anomaly of memory; it is the impression that an experience is “being recalled” which may result from an overlap between the neurological systems responsible for short-term memory and those responsible for long-term memory.

In other words, “déjà vu” is yet another careless data inconsistency situation due to poor synchronization mechanism and hectic multithreaded race-condition incidents a.k.a. “Dark-Voodoo” bugs (e.g. “déjà vu” ;-)

—

There are many ways in which the deja experience may manifest: deja entendu – already heard; deja eprouve - already experienced; deja fait – already done; deja pense – already thought; deja raconte – already recounted; deja senti – already felt, smelt; deja su - already known (intellectually); deja trouve – already found (met); déjà vécu - already lived; deja voulu – already desired; deja arrive – already happened; deja connu – already known (personal knowing); deja dit - already said/spoken (content of speech); deja goute - already tasted; deja lu – already read; deja parle – already spoken (act of speech); deja pressenti – already sensed; deja rencontre – already met; deja reve - already dreamt; deja visite – already visited and my recent favorite invention: déjà posté – already posted…