Vico Virtual Construction software

Home | Community | Vico Blogs | Vico’s Flying Dutchman

Current Articles | RSS Feed RSS Feed

#1: Why Model Based Estimating Makes Sense

October 25, 2007

In this blog, which will often be produced while being airborne, I will write about the new approach to estimating that we at Vico have been practicing for about 3 years now. It’s about a technology that has been around for much longer but has become more and more popular with the increasing adoption of Building Information Modeling. This blog is about Model Based Estimating.

One of the goals of this blog is to become a platform for people who are interested in or practice model based estimating. If you’d like to share your experiences with and knowledge of the concept, feel free to send an e-mail to "flying.dutchman@vicosoftware.com”

As a start, I want to stretch the term “Model Based Estimating”. When talking about Model Based Estimating, it is automatically assumed that it involves the use of 3D geometric building models. Although 3D building models do indeed provide great input for estimates with their ability for automated, accurate quantity take-off, model based estimates can also be based on more abstract, numerical, models (which is often referred to as “key figures”, defined in the conceptual phase of a project).

I will use the term “model” with the description that can be found in most dictionaries: “a hypothetical description of a complex entity or process”. In construction, we create such descriptions on a day-to-day basis: making abstract representations helps us to make decisions on complex situations, like the estimated cost or the budget of a project.

Both types of models (the geometric building model and the numerical model consisting of project characteristics), or also combinations of both, give estimators more decision making power. By deploying the concept, you can actually “model your estimate” by developing alternatives using models to define variations. Analyzing alternatives is easier with models because of their flexible nature; going through iterations makes it easier to decide on the best solution.

Over the past 6 years, I have been working with the concept of model based estimating. I started using the technology as an engineer at the preconstruction engineering department of a construction company and after that, I continued as member of the Graphisoft – now Vico – “Virtual Construction” team. During this timeframe, I have been involved in numerous projects, a lot of them so called “pilot projects”, in which model based estimating was explored. The projects I worked on were projects, in which model based estimating has been applied vary from projects in the conceptual phase, to projects in bid phase.

The amount of available information and the variation in this information throughout the stages of design to pre-construction differs significantly. However, for all phases, the same rule for successful deployment applies: define what your goal is before you start to create your model. Like in math: write down the problem statement and subsequently define the constraints for the model that will help you to solve it.

We also offer a step-by-step guide to our 5D virtual construction workflow with video tutorials. These videos are just 2-5 minutes in length, but illustrate how to use a particular piece of functionality. You can access the video library index and view just what you need, or download the complete set of training videos.

COMMENTS

Intresting, Can we use the architect model for estimating?

posted @ Thursday, November 15, 2007 5:38 PM by Yonit Levy


Yes, you can, provided that the model is created and properly structured according to guidelines that both estimator and architect agree upon.

posted @ Wednesday, December 05, 2007 3:19 AM by Marcel Broekmaat


Prior to running my Arch practise, I spent 15 yrs developing estimates for commercial contractors here in Chicago. I have since 1985, used computers to render building designs, but only recently tried to extract data for estimates. I have had limited experience as it seems once data is extracted, a lot of time is spent adjusting the spreadsheet to get it into a wokable format for summarizing and applying accurate pricing. Quantity estimating is certainly usefull. But it has been my experience the key to estimating is always figuring out a better way to use labor, and unitizing assemblies is one way to save on field labor. I have yet to find a modeling program that allows different methods of estimating this.

posted @ Sunday, March 02, 2008 10:57 PM by John Jurewicz


John,
Thanks for your feedback and sharing your experience with model-based quantity take-off. I agree with your statement that the real benefit of using model-based information is not found in just extracting the quantities; filtering and sorting of the extracted quantities “dumped” into a spreadsheet is time consuming and adds limited value to the iterative design and cost estimation process. Our Virtual Construction products are therefore not using that approach: elements in the Constructor model are “tagged” with knowledge data packages and quantities are automatically fed into these packages as input when published from the model. The result is an organized and automatically processed calculation of not just labor hours and cost, but also material, equipment and – when applicable – sub contractor costs. I would recommend downloading Constructor and Estimator to experience the difference with model-based quantity take-off!

posted @ Monday, March 03, 2008 8:13 PM by Marcel Broekmaat


Post Comment
Name
 *
Email
 *
Website (optional)
Comment
 *

Allowed tags: <a> link, <b> bold, <i> italics