A severe labor shortage and rapid urbanization have created a growing need for construction automation. Various tools and methods such as Digital construction, prefab, and 3DCP (3D Concrete Printing) are available for automating construction activities. These tools were invented decades ago, but 3D-Printed homes have become popular in recent years. Around the world, few builders are implementing 3DCP for the construction of houses and small buildings. Due to the cost of material and production issues, 3D printing houses is still not profitable. The public excitement has facilitated initial sales, but the early adopters are struggling to make an ROI (Return on Investment). This lack of profitability force prospective construction companies to turn away from the technology. A new technology to become mainstream, a critical adoption rate must be reached. If not, investments will dry out and the technology may get phased out. Construction automation is a pioneering field, there is no clear path to profitability. Most, if not all, early adopters of 3DCP are not making an ROI. The current automation practice is inefficient, process optimization could be a way to make 3DCP cost-competitive.
Automation was first introduced by the manufacturing sector, over the years various methodologies were used to improving the efficiency of automation. According to a 2020 McKinsey & company report, manufacturing productivity increased by 60% in last 25 years. It was the result of various improvements made in the process design (eg: Lean, SCM etc.) – robots are used for automating a process. As productivity increased, manufactured goods became cheaper. In contrast, construction productivity grew by 1% year over year for last two decades. The cost of construction is also going up. The current construction process is not compatible with automation. Since construction requires the coordination of different activities, automating it becomes complex. The construction automation companies often overlook the complex nature of the construction process. This is a reason for the high cost of 3D printed construction. Construction 3D printers are expensive, to make the initial investment worthwhile, utilization of the machines should be maximized. For this, the construction process should be optimized. There are various engineering methodologies available for optimizing processes. Systems engineering is a field of engineering that deals with the management of complex processes. System Approach is a methodology in systems engineering that can be applied to manage complex processes like construction.
System Approach to Automated construction
Systems engineering is an interdisciplinary field of engineering and engineering management that focuses on how to design, integrate, and manage complex systems over their life cycle. Some terminologies are;
System: A system is the set of principles or procedures according to which a process is done – the construction process is a system.
Sub-system: Individual elements of a system that work together to create the system
System Approach addresses one problem by considering the whole picture; the problem will be analyzed in its environment. The construction process (system) includes various activities (sub-systems) such as site work, foundation, MEP, and all other related jobs. Applying automation without considering the interfaces between these sub-systems makes the process more complex and costly. This is a major reason for the production issues faced by the early adopters of 3DCP. This article discusses the application of system approach for the development of a new construction procedure that leverages multiple automation techniques. 3DCP and prefab are two construction automation methods with complementing characteristics. A process that integrates the elements of both methods could be an optimized construction process. The management and control of such a process can be handled by leveraging digital construction tools. Integration of 3DCP, Prefab and digital construction into a single construction project will be a complex endeavor. Systems approach can be apt for developing this kind of complex process. Figure 1 illustrate the different phases of System Approach to 3DCP, in the following sections, the various phases are discussed in detail.
Figure 1: System Approach Phases
Analyze: Know your problem inside out
System Approach to automated construction is an orderly process that starts with an analysis phase. The main activity during this phase is conducting a comprehensive study on the construction process and automation techniques. The objective is to identify the opportunities for automation and predict its effects on the overall productivity of construction.
Implementation of new technology is challenging. To develop an automated construction process, the capabilities and limitations of the technology should be understood. The objective of the analysis phase is to collect as much information as possible. It will require deep and exhaustive research into problems and solutions. Some outcomes of analysis into 3DCP would be.
- Different 3DCP machines and printing mixes will be compared on price and properties. This will help to identify the most economical and robust system that can be implemented.
- Printing strategies like in-situ and print to assemble will be analyzed on their practical and economic benefits. The strategy with the best economics will be selected.
- The effects of 3D- Printed wall systems on other related works such as MEP or Finishing will be studied, all possible challenges and available options will be listed out.
The above list is not comprehensive, the analysis will cover all topics related to the construction process. This comprehensive study will help to identify the complementarity of various practices and technologies. Building a house or other structures involves 3rd party inspections and permits. The data collected for the analysis phase will help educate the 3rd parties and authorities about the viability and security of the automation processes. More data will help to substantiate the claims in front of permitting/licensing authorities. By the end of the first phase, all stakeholders in a construction project and their interests will be identified. To improve productivity a collective effort of all stakeholders is necessary. System approach to construction automation is an attempt to bring process improvement by creating harmony between various activities on and off the construction field.
Design Phase: An overview of the solution
The analysis phase will be followed by a Design phase. During this phase, a construction process that utilizing automation will start to take shape. The specifications and scope of the process will be decided in this phase of system approach. The design of the system will contain the following elements.
- The Objectives: Based on the information gathered during the analysis phase, the goals of the new system will be decided. It will be a high-level description, for example, the objective of the system can be constructing a custom-designed house in 6 weeks and at a cost 30% cheaper than to traditional process.
- The process diagram: A high-level diagram showing major subsystems and the process flow. Process diagram will provide a system-level understanding of various interfaces in the system.
- A brief description of the process: The design should contain a high-level description of the process and the inter-relations between various sub-systems. This description will be the written form of the process diagram. It should also mention the method of implementation.
- Success factors: A criteria for evaluation of the process should be decided at this phase. The system must satisfy a set of minimum requirements to be considered viable. Success factors can be revisited at any point to evaluate the progression of the system approach.
By the end of the design phase, a rough picture of the final system will be generated. In the next phase, this high-level design will turn into a detailed construction procedure.
Develop: How to achieve the objectives?
In the development phase, a detailed construction process will be created; detailed procedure describing the start to finish of the construction process. The skeleton from the design phase will provide the guideline for this phase. Developing the system requires a wide range of expertise in various construction activities. The systems engineer should know about construction 3D printing, conventional construction, structural and architectural design, and all other activities. During this phase, all the details of the automated construction process will be finalized. The development process involves the following.
- Selection of the technologies and machines required for the construction job.
- Necessary licenses and contracts will also be secured.
- Development of new construction practices – if required
- Creation of the procedure for the construction process.
- Identification of the risk factors in the process and risk mitigation measures.
- Calculating all required resources and planning their allocation.
- Creation of required standards and performance measuring criteria.
- Creation of training for all the stakeholders.
People involved in the development process should have a broad knowledge of various construction automation techniques. The development team should be both optimistic and skeptical during the development process. The team should include a skeptic of construction automation. This will help to identify the risk factors in the process. As the development progress, the original design may get changed. The initial understanding of the technologies may change and goals will have to be adjusted. Developing a system consist of various technologies is demanding. The efficiency of workflow in such a system will depend on the smoothness of the interfaces between various subsystems. Achieving this smoothness is the primary function of system approach. A construction project can be finished in multiple ways, but to create profitability the process should be as efficient as possible. Things may not go as planned when implementing new technology, multiple iterations may be required to find the right way of doing things. Multiple validations and revisions should be carried out during the development phase; correcting a mistake during development is easier than doing it during implementation.
Implement: time to break the ground
In this phase, the plans created in the development phase will be excicuted. Even though this article is mainly discussing 3DCP, the scope of systems approach to automated construction includes everything from architectural design to completing the house. The first step in the implementation is implementing the required training. All the stakeholders should be capable to perform the respective duties at the efficiency required by the system design.
Innovative design is often overrated and the difficulties of producing the design are overlooked. Production phase is the most demanding phase of innovation. Similarly in the system approach, previous phases were just conducting research and making calculations. But during implementation, the plans should be executed according to the calculations. Even in conventional construction, it is hard to execute every aspect of the project according to the plan. Most construction projects will burn more cash than the initial budget. Unexpected delays and problems are the nature of building construction, during the implementation of new technology these problems can get worse. The efficiency of the system approach will be decided by the performance of the designed system during the implementation phase. The different automation tools such as 3DCP and Digital construction must perform in real-world conditions. One important thing is to make records of the actual performance of the construction process. The records are made for each activity and technology used in the process. This documentation is important for improving the System Approach. Even after extensive research and planning there is a good chance for the process to be flawed. The initial projects will testify for the efficacy of the system approach, failure to achieve the objectives are indication of mistakes in the previous phases. Since it is the early days of construction automation, the projects can be plagued with unplanned problems. If a building project cannot be finished as per the plan, the plans may have to be changed in the middle of the implementation phase. Finishing each project and handing over them to the customers should be the primary focus during the implementation phase. Corrections to the system will be made in the next cycle. Customer satisfaction is important for the proliferation of 3D-Printed houses.
Evaluate and improve
Systems approach to automated construction is a continuous process, with each project the construction process will get better. Evaluation of the process occurs at every point of the system approach. Before moving from one phase to the next, the performance and direction of the methodology will be evaluated. It helps to keep the focus of the system development process. By the end of the implementation phase, all the performance data of the system will be available. After the conclusion of the Implementation phase, a comprehensive evaluation of the system will be conducted to identify the root causes for the problems. Even if the system performance is satisfactory, an evaluation will search for improvement opportunities.
The last phase in the system approach is to adjust the construction process for improvements. Like evaluation, improvements can be made at every point of the system approach. There is a lack of examples for automated construction projects, only a few automated building projects have been completed. Each project is a learning opportunity, improvements will be made to the process each time a house is built. Initially, the improvements will be of noticeable magnitude but after dozens of projects, the process will get perfected. Eventually, standards and benchmarks will be created for construction automation. There is a huge gap between the effectiveness of automation in manufacturing and construction. For comparison, an average car can be built in 30 hours, but automated construction projects still take months to finish. If construction can reach vehicle manufacturing productivity, an average home be finished in few weeks. By using a system approach, the effectiveness of automation can be improved.
System approach can be applied to the whole construction industry, it will create new practices and tools by considering the whole picture. Implementing a system approach in the designing and manufacturing of 3D printers and related systems will create machines that can perform better in real-world applications.
More lessons from Manufacturing
Automation was created to improve the productivity of manufacturing plants. Today most of the manufacturing plants are fully automated. Industrial automation is a billion-dollar industry. When applying automation to the construction sector, the process improvement philosophies of manufacturing should not be neglected. Manufacturing processes are being improved continuously for increasing efficiency. Factories have come a long way from the automated spinning mills of the eighteenth century. Automated manufacturing has made products cheaper and factory floors safer. Over the years, various production philosophies such as Lean, Six-sigma, Toyota Production System, Kaizen, etc. were developed for optimizing the processes. On seeing the process efficiency in manufacturing, other industries adopted some of these methodologies for designing better processes.
The initial investment for automation is huge, to make ROI the machines should be in production mode as much as possible. At present, the construction automation machines are in a state of storage or idle for most of the time. Machines are made for operation, whenever a machine is not working it is not returning the investment. Construction is an old trade, the processes were designed for human labor. To construction automation profitable, the process must be made compatible for automating. A construction process that utilizes the 3D printers to the maximum extend has to be developed. The operation of such a process may require an entirely new supply chain. By utilizing the process optimization methodology the automated construction can be made more cost-competitive.