BUILDING INFORMATION MODELLING Part 1
AN OVERVIEW OF THE PROCESS FROM AN IRISH CONSTRUCTION PROJECT MANAGEMENT PERSPECTIVE
By Paul Stewart
Abstract: The construction industry in Ireland and across the globe has not matched other sectors increases in productivity over the years. In fact, data in the US shows it has actually declined since the 1930’s. The construction industry is notoriously conservative and slow to change. Many of the same traditional procurement and project delivery formats have remained the same for decades. The aim of this journal article is to give the reader a brief overview of Building Information Modelling (BIM) to allow construction managers gain an understanding of its potential as an integrated project management tool and how its implementation into construction projects could help productivity. The paper identifies key areas of BIM and discusses their uses. It investigates the use of BIM technologies as a collaborative means of producing construction projects from inception, through planning, design, construction and finally completion. The paper identifies the stakeholders required for a collaborative process but places particular emphasis on the benefits to construction project management in areas such as scheduling, safety, constructability and control. These areas are expanded and allow specific professions to understand the interrelationship between all professions and the obvious advantage of working together.
The article relates the use of BIM to the current Irish construction industry, its current practices and some of the barriers which are in the way of increasing productivity within the industry. These include tradition, the conservative and fragmented nature of the construction industry, education, legal barriers, conflicts of interest, expense and the speed of change of available software’s. Just as it is impossible to be an expert in every profession, it is also impossible to become an expert in all areas of the BIM process. This is why an overview of the process shown in an Irish context with an emphasis on project management is so important to the industry at present. If BIM is only seen or investigated for its individual uses to each procession and not viewed in a holistic manner, a huge proportion of its potential to increase productivity in a very unproductive sector will be lost.
Keywords: BIM, Visualisation, 3D, 4D, 5D, Constructability, Collaboration, Clash Detection,Safety, Quantity Surveying, Productivity
“Building Information Modelling (BIM) is a digital representation of physical and functional characteristics of a facility. A BIM is a shared knowledge resource for information about a facility forming a reliable basis for decisions during its life-cycle; defined as existing from earliest conception to demolition. A basic premise of BIM is collaboration by different stakeholders at different phases of the life cycle of a facility to insert, extract, update or modify information in the BIM to support and reflect the roles of that stakeholder” (National BIM Standard – United States)
This article is a first stage exploratory piece of work into the functions and uses of BIM and there potential benefit to the Irish construction industry. BIM is currently not utilised in Ireland and is not understood. This work is an attempt to gather existing information and present it in a way which can help the industry to understand BIM in its broadest context and to highlight the need for continue research into specific areas by the differing professions within the industry.
The review of the literature allows the reader understand the complex nature of the BIM process. The paper does not attempt to answer all the questions about the BIM process in Ireland but rather acknowledges that BIM in its true form does not exist. The paper tries to pre-empt where the areas of further research will lie in the near further and identify areas of particular interest to many within the industry.
Currently broad explanatory or exploratory review of BIM in an Irish context exists. This paper can be a means of creating debate and encouraging the requirement for considerable continued research into this very large topic.
BIM has the potential to change forever and make redundant all previous methods of construction project delivery. The most common traditional means by which projects have generally been delivered in Irish state has not changed since its foundation and was used long before this in the UK and other countries also. The lack of current knowledge in the Irish industry may hamper the speed by which this change may take place.
The paper first briefly explains and explores all the current uses of BIM under single individual topics. Unlike previous MPM research papers, this dissertation paper has been designed to follow the layout of a journal article. Due to the broad nature of the topic and its intended aim to give an overview which can help an entire industry gain a broad understanding of BIM, it does not focus on specific areas in considerable detail. It does however, allow the reader, appreciate the wide ranging compass of BIM and direct them toward areas they believe would be of greatest benefit to them without losing sight of the overall holistic approach required to gain full productivity from the BIM process.
To this end, mainly articles from the 2007 on were studied in greater depth during the later stages of the literature review. Notes were compiled on a broad range of articles, journals and books and a literature review grid of common points was produced. These common points became the basis for the headings under which the article would be structured. This was the ideal manner to ensure that the major points and areas under which BIM was used could be discussed and information imparted to the proposed audience and to allow direction as to what future research will be required to help the Irish construction industry utilise BIM.
To date, many BIM articles simply did not appear to give all professions a good overview or understanding of BIM in its broader sense. The process was discussed under the following headings:
- Clash Detection
- Quantity Surveying/5D
- Progress Tracking
It became apparent from the common points grid which areas had been discussed in detail and which points appeared to have a gap in study into them. To keep the paper to the concise journal article type length proved most difficult and this paper reached the higher limits. It also became apparent that the current construction project delivery methods in Ireland had led to less than harmonious relationships between many of the stakeholders and that BIM’s potential to aid the entire procurement and delivery process was likely to become a future issue within the industry. Project alignment and Delivery are also discussed in both the main body and the conclusions.
From the earliest adaptation of BIM or even simple 3D modelling, it was apparent that the visualisation aspect allowed designers, owners and contractors see and comment on construction projects prior to them starting onsite. In this most basic form, it gave the stakeholders an opportunity to add or remove components they liked or disliked without incurring the same costs as they would have had during construction stage and without the same possible delay consequences. However, perhaps more importantly, it allowed on-site teams view the expected outcome and understand far more quickly what the designer expected to be built. This essentially allowed many teams on complex projects hit the ground running. As recently as 2006, many considered BIM’s primary attraction as the ability to animate designs. In a case study covered in an eminent journal at that time, it was noted “The initial and primary motivation for developing the 4D schedule was to enable non-technical senior stakeholders, who would approve the project, understand what the scope of the project was” Basu (2007).
It would of course be foolhardy not to see the merit in 4D as a visualisation tool, but in truth, it has been oversold as one of the major benefits of BIM. It has been used as a marketing tool to win contracts and frequently never used for its many other attributes. Again, much of the reason for the over emphasis on the visual aspects of 4D models up until the late 2000’s could be attributed to the available software and the difficulty in using it. Thus, BIM tended to be used only on larger projects where expertise could be employed on a full time basis. Visualisation was cited as a major contributor to the understanding of stakeholders, particularly sub-contractors on the construction of the Benjamin D. Hall Research Building, University of Washington, a complex facility. The visualisation of sequencing allowed sub-contractors see clearly where they fit in to the workflow.
‘Computer Advance Visualisation Tools’ (CAVT) (Rischmoller et al. 2006) concluded a case study which showed CAVT resulted in reduced waste, improved flow and better customer value. This cannot be attributed solely to the visual model but must also take into consideration some of the other tools implied and discussed later on. However, the study did show it was of significant effect. Sacks et al (2009) discussed the potential contributions of BIM to visualisation of the product and process aspects of construction projects in terms of lean construction principles.
Nevertheless, the benefit of visualisation remained hampered by the software and the lack of expertise available. (Benjaoran and Bhokha, 2009) noted that visualisation was able to eliminate the many different interpretations people may have had with simple 2D drawings, This lead to the ability for those involved to see omissions and evaluate accessibility within the building site.
The advancement of much of the software allows much greater means of visually representing time in BIM models. Frequently, programmes allow colour coding of building components to show what stage they are at on any give date. For example, green could indicate work in progress but not completed, whilst normally the proposed final colour of the component in question indicates it is an activity which is completed. Often a semi transparent third colour representation is added to indicate planned work vs. actual work completed. In addition to this, graphics, animations, annotations and text can be added to video schedules offering greater visual experiences. This can be a very “enlightening information medium” particularly for the non-construction stakeholder (Benjaoran and Bhokha, 2009). However, there are some drawbacks to this visual medium – it is hard to show the relationships and interdependencies between work activities or tasks. A Gantt chart can show these clearly with line and arrow links. Duration is also more difficult to show in animation models whilst progress tracking can give a unique visual view of a project at any given time, the visual aspect is not a sufficient means on its own to be considered a full progress tracking solution which would drive correctitive actions.
In the Homan high speed railway project, (Cho et al. 2011) explain the benefit of a visual model as a public relations tool. In large scale projects, it is common for the public to have a fear of the unknown. This is often borne out of a lack of understanding and knowledge of a project and its perceived impact on the locality. Visualisation helped the local population understand more easily the processes which were to be undertaken. This proved to be invaluable in getting stakeholder buy in to the project.
From an educational perspective, (Peterson et al. 2011), advocated the visualisation of a construction project as a good means of explaining a project to students in the construction field. It should be noted that many students will have spent little or no time on a construction site and so this simulation could lead to rapid understanding of some of the problems given to students by their tutors.
Finally, visualisation can be used as a basic means of looking at the sequencing of activities in relation to temporary structures, plant and temporary supports. For example, the digging of external pipe work may not be possible due to the proximity of scaffolding or temporary site accommodation at a particular time during a project. The visual benefits of BIM using 4D scheduling are not the most important aspect of this process, but can still offer significant help in defined areas and tasks.