Human Judgment Beats Simulation

Human Judgment, also known as Seat Of The Pants Analysis (SOTPA), is probably the least acknowledged but most widely used alternative to simulation. SOTPA is making decisions by instinct and feelings rather than using objective analytical tools. With SOTPA you never actually have to get out of your chair, or even spend any significant time to reach a decision.

I use SOTPA all the time and you probably do too.

When I am in a hurry to go out and want to know if I should wear a jacket or bring an umbrella, I might take a quick look out the window, reflect on the season and yesterday’s weather, then make a decision. That’s SOTPA. I know that there is a high likelihood that I will be wrong, but I don’t want to take the time to do the weather channel research to get more objective information.

Human judgment beat simulation in this case. But not always.

When I am going on an all-day outside outing and have the same decision to make; the importance of being correct increases. In that situation I will take the time to consult at least two weather sources and even step outside for some direct research. With this objective analysis I can make a more informed decision. Although such an analysis is never perfect, including objective data in my analysis dramatically increases the likelihood that my decision will be correct.

Now let’s say I am a manager and my staff comes to me proposing purchase of a new piece of equipment to solve an important problem in my facility. They may give me technical specifications, maybe some manual or spreadsheet calculations, perhaps even show me a case study about how that equipment was used in another facility. The easy thing for me to do at that point is to make a SOTPA-based decision. After all, I must be pretty smart to get to be a manager, right? Right?? 🙂 And I know THE BIG PICTURE. So who better than me to make the decision? And why should I need more information?

If you haven’t read it, I’d suggest you pause now and read the blog on Predicting Process Variability. Did you pass the test? Don’t feel bad, almost no one does. My facility is much more complicated than that one. If I cannot predict the performance of such a simple system, why should I expect that I can predict the impact of adding this proposed equipment to my facility?

“But I don’t have time to simulate.” I don’t have time to research weather when the penalty of being wrong is low, but I make the time to do it when the penalties are higher. With modern simulation tools you can often get valuable results in a short period of time. In two or three days you can often provide an objective analysis that can save a few hundred thousand dollars. Let’s see, invest $3000, save $200,000 … I think I can make the time for that. How about you?

Simulation beats human judgment when it matters.

When someone else uses SOTPA you might say they bent over and pulled the answer out of their… um, … er, shoe. “What was he thinking?” Don’t let that be you.

Reserve SOTPA for decisions that don’t matter. Use simulation for the decisions that do.

Dave Sturrock
VP Products – Simio LLC

Industrial Engineers are Happy

I just saw an interesting article written by the Institute of Industrial Engineers (IIE) citing a National Opinion Research Center study at the University of Chicago. According to that study, Industrial Engineering is one of the top ten occupations when rated by job satisfaction and overall happiness. I have long been an IE evangelist, because I feel it is a great career choice, but it never hurts to have some additional evidence.

The study goes on to evaluate compensation for each of those professions and concludes that IE’s are the third highest paid group out of those top ten happiest careers. While I think it is a mistake to choose a career primarily based on financial compensation, it is a nice bonus when a career that makes you happy also pays well.

Here is a short article summarizing the results: Industrial engineering for your mental health?

I’ve always felt that IE was one of the best career choices possible. And I think this is especially true in the field of simulation.

I personally try to visit a few high school classes each year to help students discover our profession and help motivate them to excel in the classes that they need to be successful in engineering. IIE can help you do this.

I urge you to also get involved with your local high schools and help spread the word.

Dave Sturrock
VP Products – Simio LLC

Professional Development

The annual Winter Simulation Conference (WSC) starts two weeks from today. Initially as a practitioner and then later as a vendor I have attended over 20 of these conferences in addition to dozens of other similar events. WSC is just one of many events that you could choose to attend. But why should you attend any of them?

All such events are not identical, but here are a few attributes of WSC that are often found in other events as well:

Basic tutorials – If you are new to simulation, this is a good place to learn the basics from experienced people.

Advanced tutorials – If you already have some experience, these sessions can extend your skills into new areas.

Practitioner papers – There is no better way to find out how simulation can be applied to your applications than to explore a case study in your industry and talk to someone who may have already faced the problems you might face.

Research – Catch up on state-of-the-art research through presentations by faculty and graduate students on what they have recently accomplished.

Networking – The chance to meet with your peers and make contacts is invaluable.

Software exhibits and tutorials – If you have not yet selected a product or you want to explore new options, it is extremely convenient to have many major vendors in one place, many of whom also provide scheduled product tutorials.

Supplemental sessions – Some half and full day sessions are offered before and after the conference to enhance your skill set in a particular area.

Proceedings – A quick way to preview a session, or explore a session that you could not attend. This serves as valuable reference material that you may find yourself reaching for throughout the year.

I think every professional involved in simulation should attend WSC or an equivalent conference at least once early in your career, and then periodically every 2-3 years, perhaps rotating between other similar conferences. If you want to be successful you have to keep your skills and knowledge up to date. And in today’s economy, a strong personal network can be valuable when you least expect it.

I hope to see you at WSC in Miami!

Dave Sturrock
VP Products – Simio LLC

The Last Lecture

I am taking a break from the normal simulation topic this week to mention a significant current event – the passing of Dr. Randy Pausch. Dr. Pausch was a tenured professor at Carnegie Mellon University who has become widely known for not only his life’s work, but also his recent activities.

What is significant is not the event of his death, but rather the celebration of his life. He was a very admirable person and he “retired” in a particularly admirable way. When diagnosed with an incurable and rather fast acting cancer, he chose to spend much of his final time sharing life lessons that he had learned and did so in a very upbeat and inspiring manner.

Among other things Dr. Pausch gave a very insightful, entertaining, and inspiring talk entitled “Really Achieving Your Childhood Dreams” in which he talked about his lessons learned and gave advice to students on how to achieve their own career and personal goals.

I was personally very moved by this lecture; enough so that I am using this blog post to urge you to listen to it. It is just over an hour long and I encourage you to set aside the time to listen clear to the end, because even those last minutes are enlightening. This is not new – it was originally presented in September 2007 and has been viewed an estimated ten million times. If you haven’t watched it yet, please do.

And don’t watch alone… if you have a teen or college student in your life invite them to watch with you – I think you will both find this hour to be very well spent.

You can find it at Really Achieving Your Childhood Dreams.

Dave Sturrock
VP Products – Simio LLC