An introduction to digital workflows

As can be seen in figure 1 the design of the structural element starts with analysis. This analysis takes in information from loads derived from architectural finishes, plant, wind loads and other imposed loads. Once complete, the analysis outputs information regarding the forces on a particular element. The design of this element takes in the analysis data, material factors and code-based coefficients and empirical data to design the element.

While simple to understand and easy to implement this linear workflow is incomplete. A somewhat more refined process is shown below:

Figure 2

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This illustrates that following element design, the proposed section size is put back into the original model to determine the effects of the change in stiffness on the overall frame action of the structure. This process is familiar to most engineers and may seem somewhat trivial, but it provides the basis on which we can begin to understand the process of digital workflows and the use of software in mapping these processes.

Why digital?

In reality, an even more complex workflow operates in building design. There are often more than standalone structural elements in a building, and these processes need to be undertaken for each and every element in a structure.

With relatively small structures (eg simple frame analysis) this may not seem particularly onerous – however as the complexity increases, or as the number of frames to be analysed increases so does the amount of work to be undertaken.

The problem scales linearly. If the goal was to reinitialise analysis with the new member sizes and run checks on the stiffness of the frames the problem would scale with the number of possible interactions between elements.

For a small frame, such as the one pictured, the problem would be relatively easy to solve with limited possible combinations of different stiffnesses.

With larger frames, more complex structures or more elements to consider, the complexity of the problem doubles with each additional member (figure 3).

Without consideration of the process by which analysis and design takes place, there is risk of duplication of work, errors and considerable (yet unnecessary) investment of time to undertake design checks manually.

Figure 3

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Isn’t this just BIM? 

No. The essence of computational design is to create adaptive flows of information that inform the design and eventual documentation of the structure in BIM software.

Robust digital workflows are essential for generating and modifying the information held in BIM models. The information modelling aspects of BIM are essential in taking the information produced by computational design and disseminating it amongst the design team, site operatives and future owners of the building.

BIM is a design tool, but it is primarily a product which evolves over the course of a project to contain information that will ultimately be used for procurement, costing, programming and the management of building operations and maintenance.

As design consultants our role in this process is often quite limited, on a traditional project at least. However, embedding data in our models, including specification and material data for example, becomes more important as the industry evolves through the design, build and operation phases becoming more closely integrated.

The adoption of digital workflows is key to managing this increasing amount of data efficiently and in ensuring QA and QC procedures can be managed.

Key objective – Avoiding and preventing data dead-ends

Figure 4 illustrates a common practice at many engineering design firms: a data dead-end, and poor digital workflow. In this example, data is created and recreated in parallel by several different members of the team. The result is disconnected models and difficult revision management.

Figure 4

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It is desirable to leverage technology to avoid such situations; a change in the overall architecture of the management of data within the design process may be required. When defining our workflows, you should consider not only what benefits structural engineers, but what benefits others within the team.

For example, using particular file formats and modelling practice can result in other disciplines being able to use shared parameters (most commonly geometry) and gain an overall interdisciplinary efficiency, both within your design practice and the wider project team.

The role of the engineer and technician should be carefully considered in this process as roles within the design team are becoming closely linked.

Similarly, the whole project cycle should be considered. In the case where the structural engineer may take the design to a pre-fabrication level of detail, early discussions with the fabricators and contractors to agree exchange formats and sharing common data should be considered.

Contractual issues and limitations of scope must always be considered, consideration of various suitable qualifications for sharing information must be made (eg there may be instances where sensitive information should not be given to parties who do not require it).

However, in many cases, it can be mutually beneficial to work in this manner as it is more collaborative and streamlined when it comes to reviewing the fabricator’s proposals or shop drawings –if the structural engineer is not creating them.

Beyond calculation 

The investment of resources to construct a robust and adaptable digital workflow within the design office can seem time consuming and resource intensive. There are serious considerations to be undertaken before embarking on such a process. However, the benefits will outweigh initial investment.

Providing a suitable workflow is implemented, the inherent scalability of the design process with modern computing power offers savings in time and effort for almost all scales of project. Automating calculations and modifying analysis models by simply altering base geometry can free engineers from more tedious tasks and improve the quality of their design input during the design phase.