BEM Best Practice--GIT And Building Energy Modeling (Part 2)
GIT is a version control system. The definition of version control system is: "a software tool that help a team manage changes to source code/data over time. It can help track of every modification to the code/data in a special database." (Atlasssian 2017)
GIT is like a time machine for modelers and developers. If a modeling mistake is made, modelers can turn back the clock and fix the data by comparing with previous version. Of course it has many more important features. An interesting article from Atlassian summarized how GIT is changing the operation of your business from marketing to human resources.
However, what can we benefit from GIT? I think there are three key advantages:
1. Design Reasoning
We are energy modelers, we do a lot parametric designs and design optimizations. However, sometimes, we forget what we changed that leads to a lower energy consumption (lower EUI). Through the comparing function in GIT, you can quickly identify the changes and reasons the causes.
Just like the time machine in macOS, GIT allows you to turn the clock back to where you started, so you will never worried you lost your original version. This is especially useful when you made some mistakes in parametric studies or you stuck in a debugging process.
3. Streamline a team's modeling process / Support collaboration
There are a significant amount of similarities between developing a software and creating a building energy model. In a software development team, one person is responsible for one feature, and he/she continuously updates the code or data relates to the features. A team manager controls the workflow and frequently communicate with each member to minimize any non-value added work.
For large or complex projects, a building energy modeling could take months for a single energy modeler to complete. But, if we adopt the software development structure in the energy modeling, how fast can we complete the task? A month or even worse...
It is because there is no efficient method established for such collaboration before! More energy modelers in a project may just create more mess. However, let's also think about the bright side of collaborations:
1. An energy modeler can be more concentrate on one system development: lighting, envelope, ventilation, or HVAC.
2. It is natural to distribute the computation workloads of parametric study into multiple machines.
3. Each modeler can be a QA for another modeler's work. Reduce the time for QA process.
All these benefits can be introduced with GIT. There is an interesting GIT in energy modeling scenario described by Michael O'keefe and Peter Ellis in their paper "Model like a programmer". With GIT, the collaboration can be smooth and eventually, increase the productivity of your modeling team.
(image shows a person want to merge lighting system into another model)
As the energy modeling work becomes an essential part of a design process, collaborations will become a key throughout the whole process. While manufacturing and software development are trying every possible way to eliminate the non-value added work ("wastes" in lean development theory), the building industry is still staying far behind. A report indicates that only 15% of the projects in AEC industry released by the original plan and the rest either require additional resources to complete or, unfortunately, canceled due to the inefficiency in collaboration. The GIT is certainly a technology that will make energy modelers go out of their comfort zone. But it is also one of the key elements for the future building delivery process.