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August 2016

Earned Value Management System = Get Paid!

Earned Value Management System = Get Paid! 600 374 Eric Roulo

Earned Value Management System = Get Paid!

Bottom line: you don’t get paid, if you don’t show earned value. Usually earned value is done during key milestone such as: preliminary design review (PDR), critical design review (CDR), test readiness review (TRR), first article inspection. In the real world, you will see management pushing on holding key milestone reviews, since it is associated with invoicing for payment. It is critical for engineers, managers, and supporting functions to understand payment milestone drive the schedule.

An EVMS Earned Value Management Systems is a method used to track project performance and forecast future performance. An EVMS integrates performance, cost, schedule and risk management of a project and provides early warning of risks and problems. Provides accurate response to management; are we behind or ahead of schedule, are we under or over budget, what will be spent on the whole project. It provides an EVMS and reporting system to use as a tool to manage the timely indication of work progress, early identification to problem areas, potential issues, and performance trends which give the project manager the ability to project controlling the baseline.

Table 1 Earned Value Parameters and Performance Variance

The benefits of understanding the EVMS process is that the program effectively integrates performance, time, cost, & risks. All the EVMS variables are defined in Figure 1 Earned Value Management Systems and Table 1 Earned Value Parameters and Performance Variance shows how the EVMS is measured.

History of EVMS:

Cost and Schedule Control Systems Criteria (C/SCSC) used in DoD for more than 35 years, DoD 5000 series contains 35 criteria. In 1996, C/SCSC transitioned to EVMS containing 32 guidelines. In 2003, DoD raised concerns and actioned government/industry to establish EVM working groups. In 2005, Office of Management and Budget (OMB) implemented EVMS on all federal agency capital asset acquisitions and inter-agency work.

EVMS is a requirement of many U.S. Government agencies such as: Department of Defense (DoD), Department of Transportation (DoT), Department of Energy (DoE), Department of Homeland Security (DHS), National Aeronautics and Space Administration (NASA), Federal Aviation Administration (FAA), and others. This is why you have to conform, you want their money and you want to get paid.

The ANSI/EIA-748-C EVMS Standard contains a set of 32 Guidelines that defines the requirements EVMS must meet. There are 5 phases of EVMS process:

Reference: National Defense Industrial Association, Earned Value Management Systems ANSI/EIA-748-C, April 29 2014

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Presenting FEA Results Properly

Presenting FEA Results Properly 600 374 Eric Roulo
Anytime you present data, it should be done with the intent of providing as much information as possible with the goal of preemptively answering questions the viewer might have.

Margins should be reported in tables and then supported with imagery. An expected image is the fringe plot of stress, strain, or perhaps deflection. This image is what most people perceive as the primary output of finite element analysis, but presented alone often provide misleading and partial data.

Fringe plots (contour plots) should be shown to identify where the high stress regions are for a given load case. The color bar should be discretized to aid in the understanding how large an area of a certain stress level is. The color bar should have a reasonable number of levels (i.e. 10-20). Usually the defaults are fine. The background should be white to allow for good printing (no color gradient or black background). This includes pictures for PowerPoint presentations as they usually get printed out too. Feel free to rescale the color bar to a meaningful set of numbers. The top number should usually not be the highest value reported. Make sure the post processor does show you the maximum value, usually identifying the area directly (with a number). It’s always nice to be able to see the date generated, what file the results are from, etc.

Element edges should be turned on so you can see the type of element and mesh density in the region of interest. If the element edges overwhelm the colors trying to describe the stresses, turn them off for the big picture view and then zoom in and turn them on for a detailed view.

Remove elements from the calculation that are high due to modeling technique (singularities). This will include areas where point loads are introduced, elements attached to rigid elements or near spring connections representing fasteners (among others).

A good measure of if your charts and tables are providing the correct information is if no one is grabbing a calculator or doing math on the numbers you present. If everyone is computing a ratio of your results, compute that ratio for them and report it directly.

The following Guidelines are a good start for effectively presenting contour/fringe plots:

  1. Discrete Color Ranges (level colors)
  2. Element Edges On
  3. Legend On
  4. Show Output Data
  5. Text Size 18 pts
  6. Background to White
  7. Show BC’s and Loads
  8. Specify Contour Levels
  9. No Magenta
  10. Use High-Resolution Output Images
  11. Size Image Window Appropriately
  12. Use Colors to Describe Model Features
  13. Remove Elements
  14. Show Overall and Zoomed in View

-ejr

Prepare for Your Technical Future with Dr. Richard Hamming

Prepare for Your Technical Future with Dr. Richard Hamming 549 526 Eric Roulo

hammin_102743951sm“FEA is for insight, not numbers” was the quote on the inside cover of the student guide for I-DEAS. I found out 15 years later that it was a misquote from Dr. Hamming, but that research led me to one of the great finds of my professional development. Learning to Learn is a 31 part lecture series that outlines the lessons learned from a giant in the field of science and engineering. Watch the first episode and be captivated.

The binder of Hamming’s notes contained the following, which eventually was published as a book.

The Art of Doing Science and Engineering and the ebook is located here.

The videos can be viewed on RCI’s youtube channel in a special playlist here.

“The purpose of computing is insight, not numbers.” -Richard Hamming

-ejr

Book Review – Practical Finite Element Analysis

Book Review – Practical Finite Element Analysis 300 250 Eric Roulo

Practical Finite Element Analysis, Finite to Infinite, 2008

practicalfeabook

 

I had always planned on writing a textbook on this subject because I hadn’t found one that was any good, but then I found someone had already done it in India. This book is hard to find, I found my copy while browsing the Tata Bookshop in Bangalore India after my friend Rajesh had shown me his copy. This book is so good. I hadn’t had a best FEA book on my best of book-list because I didn’t think there was one out there. This is it. It’s $10 if you pick up a copy in India, otherwise, it will cost you $85 for the international hardbound. It’s worth 5 times that much.

Reading this book is like having a casual conversation with your company’s old-timer who is full of knowledge, easily approachable, and likes to try to put things in perspective with directly actionable guidance and a good story to back it up.

How many tri3 elements are okay to have in my mesh (max of 5%). This image accompanies a discussion of what a professional mesh looks like. It’s eye opening. Do you know your mesher that well? Few if any of my ‘professional’ meshes look that good, and it inspires me to re-read my preprocessors section on meshing and be better.

The authors use Hyperworks for most of their examples, and it highlights what a very good tool Hypermesh is for meshing. The ‘rules of thumb’ are usually presented with an FEA trade study showing how the rule of thumb is actually the asymptote of a trade study. A number of detailed examples are presented, showing the reader not only how these guidelines were derived, but showing the gamebook for how to build your own rules of thumb for your application or industry. My experience is primarily aerospace, primary structure, linear stress, and dynamic analysis. In those areas, with my experience, I agreed with the recommendations.

Then, the book expanded into non-linear, fatigue, NVH (noise-vibration-harshness), crash, and CFD (computational fluid dynamics). In these chapters, it describes how meshes for each of these analyses have different requirements and demonstrates it with very good graphics. I had no idea about the limitations of crash analysis mesh quality. Crazy. The last two chapters of the book are worth the price of the entire book. They are titled “Common Mistakes and Errors” and “Preparation for Interview.” In Common Mistakes, there is an amazingly frank discussion about Engineers, Marketing, group leaders, and HR. My favorite part follows:

“9) Not CAE but Design engineer is the most important person in Design Chain: CAE Engineers are usually highly qualified, paid higher salaries and sometimes it leads to superiority complex (that they are the most important people in design cycle process). But it should always be remembered that the Design Engineer is the most important person and role of CAE engineering is to provide analysis services to him (other service providers are test, purchase, manufacturing, etc.).”

I agree. Analysis is a support role. We serve at the pleasure of the design function. A good design will succeed without all of our fancy computational models. We might be needed to justify this fact, but there are other ways: test, demonstration, similarity to previous designs, etc.

The last chapter on interviewing is very good. I’m glad I’m senior enough to not get asked a rapid-fire set of questions like the ones presented. I’m not sure if I would pass! Here’s a good one, “What is symmetric boundary condition? Can we use it for dynamic analysis?” If your organization doesn’t have good canned technical questions for CAE, this is a great starting point.

This book is a must for all analysis libraries and FEA analysts. I bought 5 copies in India to bring back and give to my clients and friends.

Practical Finite Element Analysis, Publisher: Finite to Infinite, 416 pages, $85 International

-ejr