The Software Error Reduction Plan (SERP) has four key steps. In previous columns (October 2009, January 2010, March 2010, and July 2010), we expanded upon the first three steps. In this article, we will focus on the fourth step of SERP: performing internal reviews of models.
Why perform internal reviews?
Reviewing models and projects is important because it ensures there are standard items checked in every model, keeping safeguards in place to reduce the risk of mistakes. While the engineer building the model might have a list of items he/she checks, having an additional set of eyes to review the model and provide a fresh, comprehensive perspective can be helpful. Performing the internal review ensures that someone who is not familiar with the model understands the results and, given the building design criteria, feels that the results are reasonable.
Another benefit of the internal review process is that it can provide a learning experience for the engineers in the office. When the model is built by an engineer who is younger or just starting to learn a particular program, it can provide an opportunity for that engineer to learn from others in the office. One way this can be accomplished is discussed below.
Who should be involved in the internal review process?
When deciding who in the office will be involved with the review process, there are different things to take into consideration. If a company has a dedicated quality assurance/quality control group, then it would be involved in this process. In the absence of this group, experienced engineers in the office would typically be the ones to review models. The “champion” (discussed in the October 2009 column) may or may not be part of the group involved in the review, depending on his/her experience level. However, the champion will most likely lend assistance if there is a question of where to find information in the program.
Another way to approach internal reviews is to have the engineer who created the model present it to a group of engineers in the office. He/she can explain the approach taken in building the model, and talk about his/her assumptions. The other engineers can ask questions and make suggestions, allowing the model to be reviewed, while at the same time serving as a learning experience for all of the engineers who use the analysis program.
What should be checked during the review?
The design criteria and applied loads in the model should be checked during an internal review. For the gravity design, a review of the beam designs can typically be accomplished by printing a map of each level with the sizes shown, or by using design summaries. Typically, experienced engineers already will have a “feel” for what sizes to expect, and also understand serviceability and constructability issues that the person building the model should have considered.
For the lateral design, the applied forces should be reviewed, along with an equilibrium check (perhaps by printing the foundation forces). Animated deflected shapes also are helpful in identifying possible errors. If rigid diaphragms in the software are being used, the distribution of lateral force should be evaluated closely to determine how the loads are being dragged into the vertical lateral force system, since the programs will typically report no axial force in the beams.
The suggestions above are by no means a comprehensive list of items to review. If processes and procedures were created in the office (see the March 2010 and July 2010 columns), these should provide a starting point for information to review. We also would be happy to provide you with a Microsoft Word document template to help get you started in creating your own checklist for verifying results in structural software.
Lisa Willard, P.E., and Brian Quinn, P.E., are with SE Solutions, LLC — a firm dedicated to helping match top notch structural engineers with great companies and unique opportunities. They formerly worked for a combined 21 years at RAM International/Bentley Systems and can be reached at firstname.lastname@example.org or 805-482-8436 and email@example.com or 616-546-9420, respectively. Visit our new technology website, www.FindYourTechnology.com.