Archive for the ‘Success Skills’ Category

Six Sigma and Simulation: Part 1

Sunday, November 30th, 2008

By Jeff Joines (Associate Professor In Textile Engineering at NCSU)

This is a three part series on Six Sigma, Lean Sigma, and Simulation. The first blog will explain the Six Sigma methodology and the bridge to simulation analysis and modeling while the second and third parts will describe the uses of simulation in each of the Six Sigma phases and Lean Sigma (i.e., Lean Manufacturing) respectively.

“Systems rarely perform exactly as predicted” was the starting line for the blog Predicting Process Variability and is the driving force behind most improvement projects. As stated, variability is inherent in all processes whether these processes are concerned with manufacturing a product within a plant, producing product via an entire supply chain complex or providing a service in the retail, banking, entertainment or hospital environment. If one could predict or eliminate the variability of a process or product, then there would be no waste (or Muda in the Lean World which will discussed in a third part) associated with a process, no overtime to finish an order, no lost sales owing to having the wrong inventory or lengthy lead-times, no deaths owing to errors in health care, shorter lead times, etc. which ultimately leads to reduced costs. For any organization (manufacturing or service), reducing costs, lead-times, etc. is or should be a priority in order to compete in the global world. Reducing, controlling and/or eliminating the variability in a process is key in minimizing costs.

Six Sigma is a business philosophy focusing on continuous improvement to reduce and eliminate variability. In a service or manufacturing environment, a Six Sigma (6?) process would be virtually defect free (i.e., only allowing 3.4 defects out of a million operations of a process). However, most companies operate at four sigma which allows 6,000 defects per million. Six Sigma began in the 1980s when Motorola set out to reduce the number of defects in its own products. Motorola identified ways to cut waste, improve quality, reduce production time and costs, and focus on how the products were designed and made. Six Sigma grew from this proactive initiative of using exact measurements to anticipate problem areas. In 1988, Motorola was selected as the first large manufacturing company to win the Malcolm Baldrige National Quality Award. As a result, Motorola’s methodologies were launched and soon their suppliers were encouraged to adopt the 6? practices. Today, companies who use the Six Sigma methodology achieve significant cost reductions.

Six Sigma evolved from other quality initiatives, such as ISO, Total Quantity Management (TQM) and Baldrige, to become a quality standardization process based on hard data and not hunches or gut feelings, hence the mathematical term, Six Sigma. Six Sigma utilizes a host of traditional statistical tools but encompasses them within a process improvement framework. These tools include affinity diagrams, cause & effects, failure modes and effective analysis (FMEA), Poka Yoke (mistake proofing), survey analysis (voice of customer), design of experiments (DOE), capability analysis, measurement system analysis, statistical process control charts and plans, etc.

There are two basic Six Sigma processes (i.e., DMAIC and DMADV) and they both utilize data intensive solution approaches and eliminate the use of your gut or intuition in making decisions and improvements. The Six Sigma method based on the DMAIC process and is utilized when the product or process already exists but it is not meeting the specifications or performing adequately is described as follows.

    Define, identify, prioritize, and select the right projects. Once selected to define the project goals and deliverables.
    Measure the key product characteristics and process parameters to create a base line.
    Analyze and identify the key process determinants or root causes of the variability.
    Improve and optimize performance by eliminating defects.
    Control the current gains and future process performances.

If the process or product does not exist and needs to be developed, the Design for Six Sigma (DFSS) process (DMADV) has to be employed. Processes or products designed with the DMADV process typically reach market sooner; have less rework; decreased costs, etc. Even though, the DMADV is similar to DMAIC method and start with the same three steps, they are quite different as defined below.

    Define, identify, prioritize, and select the right projects. Once selected to define the project goals and deliverables.
    Measure and determine customer needs and specifications through voice of the customer.
    Analyze and identify the process options necessary to meet the customer needs.
    Design a detailed process or product to meet the customer needs.
    Verify the design performance and ability to meet the customer needs where the customer maybe internal or external to the organization.

Both processes use continuous improvement from one stage back to the beginning. For example, if during the analyze phase you determine a key input is not being measured, new metrics have to be defined or new projects can be defined once the control phase is reached.

Now that we have defined six sigma, you may be wondering what is the bridge to computer simulation and modeling. Simulation modeling and analysis is just another tool in the Six Sigma toolbox. Many of the statistical tools (e.g., DOE) try to describe the dependent variables (Y’s) in terms of the independent variables (X’s) in order to improve it. Also, most of the statistical tools are parametric methods (i.e., they rely on the data being normally distributed or utilize our friend the central limit theorem to make the data appear normally distributed). Many of the traditional tools might produce sub-optimal results or cannot be used at all. For example, if one is designing a new process or product, the system does not exist so determining current capability or future performance cannot be done. The complexity and uncertainty of certain processes cannot be determined or analyzed using traditional methods. Simulation modeling and analysis makes none of these assumptions and can yield a more realistic range of results especially where the independent variables (X’s) can be described as a distribution of values. In Six Sigma and Simulation: Part 2, a more detailed look at how simulation is used in the two six sigma processes (DMAIC and DMADV) will be discussed.

Professional Development

Sunday, November 23rd, 2008

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

Read My Project Report!

Sunday, November 16th, 2008

I read a lot, both for business and pleasure. But it seems I never have enough time. So when I sit down with a magazine, for example, most articles probably get less than a couple seconds of attention. Unless an article immediately captures my attention, I quickly move on to the next one. I know that I occasionally miss out on good content, but it is a way to cope with the volume of information that I need to process each day. Consider the implications when you are writing a project report for others to read…

We are all busy. When we are presented with information to read or review, we often don’t have time to wade through the details to see if the content merits our time.

Tell me the most important thing first! Give me the summary! How many times have you asked (or wished) for that?

At one point, it was common to give presentations by starting with an introduction, building the content, and ending with the conclusion – “the big finish”. While this is appropriate for some audiences, many people don’t want to take the time to follow such a presentation. Instead, they want to be presented with a quick overview and a concise summary first. They will then decide to read on if the overview has captured their interest and they need more information.

Think about your own experiences. When you have a document to read and you are not sure it is worth your time, what do you do? If you are like most people you will probably consider most, if not all of the following:
• Does the title look interesting?
• Do you know/respect the author?
• Scan the major headings or callouts for content of interest.
• Scan any pictures/diagrams for content of interest.
• Evaluate the summary or abstract.
While the order and details might differ slightly, at each stage of the above process if you are not convinced of the value of continuing, you will put the document aside. Only after the document has passed this gauntlet of tests, will you spend the time to seriously read the content.

What can we learn from this?

Content is not enough. The best content in the world is of little value unless it is read.

When you are preparing a project report, try to get inside the head of your target audience. If you expect that they will also have a process something like the above, spend adequate time on those parts. Take an extra minute to create an interesting title. Add major headings and callouts to help focus the reader’s attention. Add some figures to help convey and support your message. Have a good abstract and/or summary that is easy to find to help your audience quickly get the point of your report.

Write each report so everyone, including your busy stakeholders, will take the time to read it. Keeping these simple suggestions in mind will help you succeed at getting your message across.

Dave Sturrock
VP Products – Simio LLC

Help Wanted

Saturday, October 11th, 2008

Yes, it looks like hard economic times may be coming. But no, this has nothing to do with that.

This blog is a community service. To continue to be effective, we need community participation. That means you.

There are many ways you can participate.

1) Comment – At the end of each article is a link. Click it and add to the discussion. Agree. Disagree. Add new information or a different viewpoint. All civil discussion is welcome.
2) Suggest Topics – Contact me with any ideas you have about future content or ideas for making the blog more useful.
3) Write an Article – It doesn’t have to be rocket science. Nor does it have to be long or formal. Everyone has something to share. The main rule is to keep it unbiased and non-commercial. I am happy to edit it if you like and even publish it under a pen name if you are publicity shy (although I strongly prefer using your real name).
4) Become a Guest Author – I would like nothing better than to “share the limelight” with others. You can write one article or regular articles. Choose your own topics and frequency.

It’s all about sharing to help the simulation community. This is a simple way to give back. Anyone can do it. For any of the above or other ideas, you can contact me using dsturrock at Simio dot biz (name slightly obscured to slow down spammers).

Thanks for your help.

Dave Sturrock
VP Products – Simio LLC

Simulation Expertise through Tours

Sunday, September 7th, 2008

This past weekend I had the good fortune to be invited to a tour of Ernst Conservation Seeds sponsored by the Soil and Water Conservation Society (SWCS). Ernst is a small company that raises and sells specialty seeds used primarily in seeding conservation areas like wetlands. But more on that in a minute…

One key to success in simulation is your ability to understand the systems being modeled. Education and experience both play an important role in this, but there is something else you can do that expands your knowledge base and is interesting – facility tours.

Facility tours (plant tours) offer a rich hands-on environment. In my experience, most are conducted by a domain expert (often an Industrial Engineer or equivalent) who knows both the facility and how to “speak your language”. Most will take you through the “behind the scenes” parts of their facility. I usually find guides to be both willing and able to explain how things work and discuss both their successes and their remaining challenges. These tours can be an incredible way to experience new things and get great new insights.

Where can you find tour opportunities?

The easiest way to get involved with these types of events and continue to enhance your understanding of systems is to participate in professional societies. The local chapters of groups like the Institute of Industrial Engineers (IIE) and the Society of Manufacturing Engineers (SME) are known for frequent facility tours. But don’t stop there. There are many other professional, industry, and technology groups like banking, healthcare, and plastics that offer tours.

Major conferences often have facility tours available as well. IIE usually has several tours available at their annual conference. Likewise some user groups and educational gatherings from major companies often include facility tours.

Ask your associates working in other companies if they could possibly arrange a personal tour where they work. If you are interviewing for a job, sometimes it may be appropriate to ask for a tour of their facility. And sometimes you can even find public tours like a beer or candy manufacturer (don’t forget the free samples :-)). Or simply get a few people together and organize a tour of your own to explore a topic you are interested in.

Don’t limit yourself to just your area of interest/expertise. Often you can learn even more from tours outside your comfort zone. You might question if I could learn things pertinent to my job by touring a small seed company like Ernst. Not only was it generally interesting, I learned quite a bit about their system as I toured their preparation, sorting and processing. I was particularly interested in their innovative work making biomass into a more effective fuel source (like a process to turn fast-growing native switch grasses into efficient fuel briquettes).

I take every possible opportunity to tour a facility. I encourage you to add frequent facility tours as part of your own continuing education and success in simulation.

Dave Sturrock
VP Products – Simio LLC

Keep Simulation Projects Simple Too

Monday, September 1st, 2008

We all have stories about company decisions that make us shake our head. If you have ever worked for a large organization, it may have seemed that some of their decisions were, shall we say, sub-optimal.

For example, one particular organization was using a “home grown” time reporting system that was simple, efficient, and worked well. However upper management felt the need to buy a more sophisticated “name brand” system. Unfortunately it was poorly designed and overly complicated. Rollout required extensive training and retraining to learn the simplest tasks. It was so difficult to use that many employees simply stopped using it in favor of informal arrangements with their managers (who also found it difficult to use). As a result, the company spent a lot of money and wasted a lot of employee time, and in the end they had a system that produced inferior results.

If this was an isolated case, it could be easily forgiven. But I expect most people working for large organizations could cite similar situations. Large organizations often tend to replace simplicity with complexity.

Last week in Keep Simulation Simple I talked about KIS; the Keep It Simple concept of doing just enough to do it well and no more!

I discussed how KIS could be applied to model building, but you can also extend the KIS principle to many other aspects of simulation, especially the tools you routinely use.

For time tracking, you can buy expensive highly integrated software systems like the organization above, or for desk- bound employees you can buy software that will sense or periodically ask and record what you are working on. But the cheaper, simpler and more effective solution is simply using a spreadsheet or paper form and having the employee take two minutes at the end of each day and record time against their tasks for that day. Sure there can sometimes be reason for other methods, but for the majority of us the spread sheet solution is superior.

For project management, choose the simplest tool that will meet your needs. Some projects are complex enough that they need project management software like Microsoft Project or something even better. But in many cases, such software results in a waste of time when a simple spreadsheet could meet your needs. In my experience project management software is often overkill for the types of projects we usually encounter.

In simulation software there is some inclination to buy the most comprehensive software that you can afford. But it is often better just to buy the simplest software that is likely to meet your short to intermediate-term needs. An important caution here – make sure that your software has an adequate upgrade path so that as your needs evolve you can migrate into more feature-rich software without losing your initial investment in software, training, and models.

Stay vigilant for time wasters – they often come disguised as “cool technology” and “time savers”.
Keep It Simple.

Dave Sturrock
VP Products – Simio LLC

Keep Simulation Simple

Monday, August 25th, 2008

I mentioned a while back that I am a Boy Scout. OK, maybe my boyhood days are long gone, but I still consider myself to be a Scout. I learned many lessons as a Scout; lessons that continue to serve me well today. One of those is KIS or Keep It Simple.

I remember learning primitive camping skills. Many novice campers would bring too much gear, requiring hauling and storing it, and just in general complicating camp life. The simple (KIS) approach is to bring only what you absolutely need. Many novice campers would also select poor camp sites and then spend time dealing with dampness, bugs, discomfort, safety issues and more. The simple approach is to avoid those issues by selecting a good camp site. Then in both cases, you spend all that saved time enjoying the camp and doing what you came to do. KIS pays off.

KIS applies equally well to many aspects of simulation. When things go wrong, it can often be traced back to too much complexity.

  • How many people are subjected to overly complex management procedures?
  • Are the procedures used for planning and tracking your work making the most effective use of everyone’s time?
  • Is every aspect of your work done effectively?
  • The basic concept of KIS is to do just enough to do it well and no more! Does this mean you should not do your best? No. But it does mean that you should segment your work into small phases and KIS on each phase.

    In model-building for example, let’s say a stakeholder expresses desire for a detailed model for the 10 areas of his system. One common approach is to go off and create exactly what the stakeholder asked for. Unfortunately, this will probably be wrong. A better approach is to pick one representative area, and do a very high-level model of that one area. Then review that model and results with the stakeholder. In most cases, you will both learn a lot and you may jointly decide on a different approach. Then perhaps do a detailed model of that same area or perhaps extend that high-level model to a few more areas. Again you will probably learn something that will change your approach or objectives. For each phase, you want to do the simplest thing (KIS) that will meet the objectives for that phase. In this way, you will minimize any wasted effort and come much more quickly to exactly what the stakeholder needs.

    Let’s consider model-building at a much more detailed level. A common mistake by novices is to build a large section of a model (perhaps even an entire system) all at once. And then you hit “Go” and it does not work. Why doesn’t it work? There are perhaps a thousand possible reasons to investigate. Even worse, there are most likely dozens of small or large problems, each potentially obscuring the others. Verifying and validating such a model is a daunting task. A much better approach is to start by selecting a very small (KIS) portion of the model to build and verify that it works. Then repeat. When a problem is discovered in any new section, it is generally easy to find it because you know it is a result of that latest section just added. Again, “Keep It Simple”.

    Remember, Keep It Simple. Work effectively and exceed your stakeholder expectations one simple step at a time.

    Dave Sturrock
    VP Products – Simio LLC

    We Are Not Making Swiss Watches

    Saturday, August 16th, 2008

    Please bear with me while I mention three apparently unrelated topics.

    I have a very good friend Harry who often offers me advice. Fortunately for me, the fact that I don’t want the advice has no impact on whether I will receive it. 😉 I have to admit that on those rare occasions when I have been accused of expressing some wisdom, it can often be traced back to conversations years ago with Harry. I always admired his ability to “cut to the chase” and identify what is really important.

    For those born into the age of digital watches, it was not too long ago that most watches were completely mechanical with lots of moving parts. Expensive watches were made with high precision and featured exceptional accuracy. Less expensive watches were made to lower tolerances and did not keep time quite as well – every now and then they might need to be slightly adjusted to reflect accurate time. If you really needed to always have the correct time, you would want to have a watch made by the Swiss, since they were world-renowned for their quality. Unfortunately, Swiss watches also commanded a very high price and most people could not afford that luxury. However, most inexpensive watches were still good enough for typical day-to-day use.

    Building models is fun and addicting! When building models it is very easy to get so involved that you forget the big picture. This is equally likely to happen when attempting to get some model detail “just right” or fine tuning an animation to make it more life-like. For example, I once modeled a material handling system where I was helping to evaluate and fine-tune several competing designs. After I had completed the model, I found myself spending hours fine-tuning the animation of AGVs unloading onto the processing devices.

    So how are Harry’s sage advice, Swiss watches, and modeling related? Quite frequently when Harry would find me working on a model aspect like the one above, a typical conversation went something like this:

      Dave: “Arrgh! I can’t get this exactly right.”
      Harry: “Are the results correct and validated?”
      Dave: “Dead-on.”
      Harry: “Can someone look at the animation and understand what is happening?”
      Dave: “Yes.”
      Harry: “Well Dave, you are not making Swiss watches here…”

    This was Harry’s way of bringing me back to focus on what is really important. While everyone wants to have the most realistic model and animation, for the vast majority of projects that level of realism is no more necessary than a Swiss watch. That’s not to imply that shoddy work is acceptable. Shoddy work in never acceptable – every project should be completed at least at the level of detail and quality necessary to meet the project objectives. But even though an extra level of realism is nice, it’s a luxury that most cannot afford. And that is especially true if spending time on the luxuries causes you to neglect the basics.

    In fact, you should apply this concept even more broadly. When a project is not going as well as expected, first look closely to see if you or anyone involved is spending valuable time on things that are not absolutely necessary. If so, refocus on your priorities.

    I urge you to join me following Harry’s advice: Concentrate on the basics first and leave the “luxuries” for later.

    Dave Sturrock
    VP Products – Simio LLC

    Executing a Simulation Project for the Simple Minded

    Sunday, August 10th, 2008

    This week I thought I would step back and offer a somewhat light-hearted summary of some of the things we have covered. Here are five simple steps for executing a simulation project.

    1. Figure out what to model. You can do this by being brilliantly insightful (which you might be), or by just talking to some stakeholders. Ask them questions. How would you use this model? What are your problems? What type of solution are you looking for? Will you invest time in this? Will you make decisions based on this model? Are you going to roll your eyes and laugh out loud once I leave the room? Are you going to tell your spouse about this project over dinner this evening to demonstrate that you indeed do have a sense of humor?

    2. Build something. It doesn’t have to be the world-changing model you devised in step 1, but a close enough approximation. It should do at least one useful thing from the list of game-changing things that’s on the feature-list from #1. Oh, and it should sort of work (even if requiring the assistance of some chanting, prayer and promises to recycle more).

    3. (Option A) Deliver it! Get your project in the hands of users. Even if it’s incomplete and not fully validated. It is possible that everyone that sees it runs screaming in the other direction. Mothers protect their children in its presence. But, get it out there and work like heck to deal with the aftermath of the great steaming heap you’ve unleashed upon the world.

    3. (Option B) Make Perfect, Wait, Deliver it! This avoids the problems with Option A because people will no longer run screaming. But, nobody cares about your project now because everyone is flying around with jet-packs on their back and 16-core processors are embedded in people’s brain as an outpatient procedure. The problem moved on and your solution (however “perfect”) is now irrelevant.

    4. Present. Present. Present. The law of large numbers says that the larger the number of stakeholders exposed to the project (see Step 3a), the more people you’ll encounter with average coordination who will trip and fall when trying to run away from your solution. Some of these people will buy-in while still in a semi-dazed state. Voila! You have happy stakeholders.

    5. Refine. Armed with a few active stakeholders, see what you can learn from them. What are they trying to accomplish? How do they use the model? What do they say between the screams of frustration? Figure out how to lower the pain quickly and treat them gently. During these brief spites of happiness that your stakeholders have, other stakeholders who come into contact with them think “Hey, Joe seems to be happy — even though he’s got this far-away look in his eyes, maybe this model is useful. Let me try it out…” Bing! You have another “happy” stakeholder.

    And the story goes on.

    For the really, really simple minded here’s the summary:
    Decide what to model, complete an imperfect prototype, get stakeholder buy-in, keep improving, get more stakeholder buy-in. Lather, rinse, repeat. SUCCESS!

    Thanks go to Dharmesh Shah of the OnStartups blog who provided the basis for this article. For anyone who has ever been, or wanted to be, part of a startup, you might find this blog interesting and entertaining.

    Dave Sturrock
    VP Products – Simio LLC

    The Last Lecture

    Sunday, July 27th, 2008

    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