BUILDING INFORMATION MODELLING Part 3
As noted in the introduction, many of the headings discussed overlap. This is in fact a symptom of the collaborative and integrated nature of the BIM process. This collaboration ensures that there is a constant intermingling of information through process. Many commentators are at pains to point out that BIM is not simply technology but a process that requires the use of available 3, 4, 5D etc technology and the collaboration of users, constructors, designers owners and end users to extract the most benefits from IT. Items such as visualisation and particularly constructability require a collaborative approach to be useful.
Basu (2007) understood the requirement for early stakeholder involvement in the process. Some of the greatest drivers of the collaboration and integrated agenda were in the US. The General Services Administration (GSA), an independent US government agency tasked with supplying office space to the federal government mandated the use of BIM and 4D scheduling by 2007, acknowledging the potential of BIM. Another major driver of BIM was the Construction Users Roundtable (CURT). This organisations members includes virtually all the multinational which are present in Ireland today, such as Abbot, Baxter, Intel, Johnson & Johnson, Eli Lilly etc.
Intel in Ireland have started using BIM extensively in the planning of its latest expansion. Full design of these plants are not fully complete when construction begins so they are dynamic environments which are in constant design development. It is certain that this project could not be delivered successfully without this collaborative and technological approach.
BIM works particularly well as an aid to the integrated project delivery (IPD) approach. This approach requires the use of collaborative agreements which can help “harness the power of BIM and Lean Construction Methods” Salmon (2008). He believes corporations who use these processes can leapfrog many of their competitors through efficiency savings.
We are well aware that Partnering or Alliancing are not new concepts. These are not agreements which can suit everybody. Procurement rules in Ireland and the EU make them very hard to enter into on public contracts. There is currently no contract available to the government which they could use. In fact, the current GCCC forms of contract specifically attempt to remove all risk from the client and place it on the contractor’s door. This adversarial contract has lead to many arbitrations and litigations and indeed several contractors have failed to finish many of these contracts due to financial difficulties. It is currently very hard to see how the Irish state could harness the potential benefits of this collaborative approach given their intent on using what are widely acknowledged as the most unfair contracts in Europe or the developed world.
Below is a table produced by Salmon (2008) showing the differences between the collaborative and the combative mindsets?
|Target Cost Estimate
|Target Cost Adjustments
|Waive Liability Claims
||Shift Liability Claims
|Serves as a Constitution
||A Draconian Code
The idea with the collaborative approach is to eliminate all non-value adding work (Tulke, Nour and Beucke 2008). This requires that “scheduling runs concurrently with other key processes like architectural design, cost estimating etc” One of the major problems with the construction industry is its inherent fragmentation. Disciplines and professions have always worked apart. Architectural firms, Mechanical and electrical consultants, fire consultants, acoustic engineers, structural engineers etc are often different practices and even when they are under the one practice name, they are often run as separate entities. This has lead to constant duplication due to under sharing of drawings and models.
The advent of BIM as the current trend has forced disciples to look differently with regard to its implementation. Particularly if it is being driven by people who will become potential future clients of all the suppliers of these services. Additionally, having used the process, many designers understand the benefits in reducing their own time on the process. They are not being asked to redesign at a later stage because these issues have been discussed and solved collaboratively, have become evident through the shared model and clash detections.
True collaborative approaches require incentivisation to ensure the team have reason to work together. This is normally dealt with through a sharing of gain as well as a sharing of the pain. The idea is that savings made for the client either in the short or long term will be partially shared out with the other stakeholders. Conversely, mistakes made later on in the process can also lead to deductions in profit. However, the use of full BIM with IPD is likely to be a slow process to become widespread throughout the industry. There are many issues such as education, trust and legal issues which will first need to be addressed.
Increasingly, 5D models are being produced which include links with the 3D model, the 4D schedule and the 5D cost and quantity estimates. The quantity surveying practices are also key to full collaboration. With the use of the quantities taken off and a list of their locations, the construction manager can advise and decide on productivity rates and thus make educated assessments on the durations of activities.
Koo and Fischer (2000) concluded in a feasibility study carried out on commercial construction projects, that 4D scheduling helped accelerate understanding of construction works. The sharing of data centrally is also one of the effects of a collaborative approach. Generally the master model is held remotely while different professions and disciplines feed into the model. This helps the model remain a live document and reduces the need for duplicating of works. The sharing of data has its own legal issues in relation to ownership of components, copyright and commercial secrecy or sensitivity. However, there are good examples available on how to overcome these issues and how successful these collaborative processes can be. As previously discussed, Sutter Health project in Castro Valley completed a $320 million project having entered into a collaborative agreement with its designers and contractors as did the University of Washington in relation to Benjamin D. Hall. There are of course many other success stories along with stories which have ended in the courts.
Safety is perhaps an area under explored in relation to advancements in construction technologies. BIM and 4D scheduling have shown very exciting potential and advancements in this area. Limited amounts of work were done in this area in the early part of the last decade and before. However, once again, with the advancement of technology, many integrated technological and construction management practices that can help reduce injury and deaths have emerged. At a very basic level, the use of BIM has dramatically increased accuracy and confidence in project documents such as design drawings and models. This in turn has lead to an increased ability to prefabricate many components previously constructed on site. Most prefabrication plants have much better safety records than dynamic construction sites. They use far more automated machinery and systems in a much easier to control environment. This reduces the time spent on site and the resources required on site.
Regardless of the complexity of the projects constructed, it is likely there will need to be temporary structures formed during construction. These could be temporary roads to gain access around the building, scaffolding to construct blockwork or install windows, canteens and offices to service the site population, security camera poles, fencing, access platforms, cranes, structures to support components in temporary states. Etc. The list can seem almost endless. All these items take up space on a site and depending on the method of construction and the equipment employed; they can dramatically reduce the spaces one has to work in on sites. They can also easily restrict access to important areas of work. For example, if scaffolding was placed between an existing building and a proposed new building, it could restrict any access between the two buildings, if pipework or services were to be laid, the scaffolding might need to be removed. 4D scheduling allows someone to physically see these problems scheduled in durations. Pipework beside scaffolding could have subsidence issues and slippage. Benjaoran and Bhokha (2009) noted its ability to analyse congestion and accessibility to working space more effectively than standard Gantt charts. This is because Gantt chart has representations of time and activities in text and bars. The do not represent time and space.
Of course, these visual representation tools are helpful but there are far more powerful tools which can help safety standards improve. Particularly in relation to the structural stability of permanent structures whilst in a temporary state during construction. The structure is dynamic and thus constantly changing. A very simple example is that of building a single steel column on its own in a sky scrapper to the top. We know that without lateral support of further beams and columns, it will fall over, buckle or pull from the foundations. Insitu concrete is in need of even more analysis as it begins as a liquid and takes 28 days to reach its final characteristic design strength. Until it reaches this required strength, it cannot be used for the purpose it is designed for, however, during construction; it will be put under entirely different structural criteria. All these constantly changing dynamic loads require temporary treatments and supports. However, without 4D schedules, the model, unlike a building remains in static state. By linking time to these structural components, it is possible to carry out time related structural analysis using the actual structural model in BIM. If this is carried out at design stage, it may determine the preferred material and the construction methodology in order to save time and money. Hu and Zhang (2011) developed a system which addressed 3 elements of safety in 4D. 1) 4D structural safety analysis. 2) 4D construction conflict management analysis. 3) 4D layout collision analysis and management. This wide ranging dynamic tool could improve safety dramatically within the construction industry.
On the Homan High Speed Railway, they also carried out safety analysis by running a model showing equipment in virtual operation first. This helped eliminate congestion and accessibility issues on site. Equipment can be shown arriving and leaving site at anytime. Additionally, a safety avatar was added to the updated progress model and could visit the site remotely. The main benefit of the avatar is to help train others. Data is embedded in the model showing current codes of practice and risk assessments.
This training element extends to formal education in construction management courses such as those in the Managing Fabrication and construction class in Stanford University and Integrated Project Management class in Twente University. Students and newly qualified graduates cannot hope to understand the construction industry without experience or at the very least without having had realistic or actual problems presented in a medium such as BIM. It allows them a greater understanding of the direct consequences of sequencing in 4D. “While mistakes in the classroom result in lower marks, mistakes in the field can affect morale, waste resources, and in the worst-case scenario cost someone’s life.” (Peterson et al. 2011).
It has long since been acknowledged that the removing of human decision making in certain circumstances will obviously result in the removal of human error. This has been done in construction in many forms such as the advent of structural analysis tools and packages, better testing equipments and regimes among many other advancements. These technological advancements can also remove some safety uncertainty in construction. Zhang et al (2012) used BIM to include algorithms which can create rule based checking systems for safety. Initially this was concentrated generally on falls from height as they represent the greatest cause of fatalities in the USA which is also true in the Irish construction industry. This rule based system was integrated into the 4D schedule also. As openings in floors or leading edges appear during construction, the rule based system would determine the treatment required for these. The algorithms would be written based on current legislative requirements and best practice. For example, if the drop was less than 300mm it might suggest simple signage and warning tape. If the fall drop was greater it would suggest handrails 1.1m high. If and opening was less than 500mm x 500mm it might suggest covering it or if less than 50mm doing nothing at all. This system can remove the danger of humans simply forgetting legislation or not getting to the problem. It can direct general labour to keep up with the safety requirements without first having to get direction from safety officers. All too often, accidents occurred because a simple solution had not been prescribed due to management not having gotten to the problem in time.