When an organization implements BIM, it is not simply adding a new BIM function to its existing business.  If implemented fully, the core processes will change and BIM will affect everyone and everything in the organization.  This article continues the theme of resistance of change to BIM-powered business, and focuses on Estimators.

Estimators

When we started to help General Contractors re-engineer their business processes to leverage the full benefits of BIM and integrated workflows, it came as a surprise that there is very little science or data behind today's estimates.  Creating a Standard Database for an organization proved to be difficult because there was no data.  Executives of multiple companies were sure that the data was there but after numerous starts and stops, we came to the conclusion that this data existed only for self-performed work.  For subcontracted work, the estimators relied on their subcontractors to provide estimates.  The skill of the estimator was to ask right questions from right people, and the successful estimators knew the subcontractors who would give reliable information for estimates.  This process did not require detailed understanding of quantities or unit prices.

Model-based estimating starts from a detailed quantity takeoff of the construction 3D model (at Vico, we call these construction-caliber quantities, and they serve as the linchpin for model-based scheduling and estimating).  The Estimator needs to define line items which will be quantified based on model data.  Because the downstream processes of model-based scheduling, procurement, and on-site production control will use the same data, it is important that the line items are determined as a team process (for more information on model-based scheduling, please review the recorded BIM 401 webinar from the BIM Master Class Series).  It is important to understand that this hand-off of information between the roles (estimator à scheduler à production control) was very limited in the traditional process.  Schedulers never used quantities and site people did not believe that they could get useful information from their estimators.  The Estimator then needs to apply unit rates for each quantity.  This is complicated because the data is not likely to exist today. To be useful downstream, the unit rates need to be separated to labor and material costs - also for subcontracted work.  The logical way to build this information is to ask for detailed breakdowns from trusted subcontractors (for more information on model-based estimating, please review the recorded BIM 501 webinar from the BIM Master Class Series).

All of this is new, so it is no wonder that estimators feel threatened by the new process.  Instead of just estimating an accurate GMP, estimators are now required to provide information which is used by the scheduler to build and optimize the schedule, and by the site guys to buy out the project and to control production (for more information on this preconstruction and production control workflow, please review the recorded BIM 502 webinar).  It would be easy, even motivating, if all of this was just better use of information which was already available.  However, because of lack of data, the information needs to be collected, and the estimators feel threatened by the huge new responsibilities they are suddenly getting.  Everyone will use the information and blame the estimator if it is wrong or not detailed enough!  The biggest threat is that the model makes the estimate and all the underlying assumptions totally transparent.  Double clicking an item in the estimate highlights the item in the model.  It is impossible to "hide" dollars any more.

The resistance of estimators typically manifests as downplaying the importance of detailed cost data, and emphasizing the risk of showing model quantities to subcontractors.  They also often highlight the difficulty of getting the information from subcontractors.  Often estimators continue to do their work in parallel with a Virtual Construction group building another model-based estimate with subcontractor data.  This has the same problem as building parallel schedules.  It is not only wasted effort to do things twice, but all downstream processes prefer to use a familiar source of information if it is available.

To overcome resistance, the estimators should be supported in the transition.  Instead of making them the only responsible party for the correctness of data, a team effort should be initiated to collect the initial set of data.  Ideally the team would include people from the site team, scheduling team, virtual construction team, and estimators (for more information on this workflow, please review the recorded webinar, Vico Office for Preconstruction and Estimating Teams).  Because the line items do not currently exist, they should be developed with the end-users in mind.  All quantities and information should be reviewed together with the team to ensure that they are correct.  If they are incorrect, the team takes joint responsibility. Estimators then use this jointly-created information to build the GMP, schedulers and site team use it for scheduling, buy-out and production control.

It is too much to expect one person to create and take responsibility for all this information.  By making it a team effort, the responsibility can be divided.  In the longer term, the estimator can start to manage it all which will give him/her a lot of power in the organization.

To see how estimators and schedulers work together in the 5D BIM Workflow, we 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. We have training levels for Estimators, Schedulers, Supers, and anyone who does CM Reporting.