BIM; What is it? What can it become?
[Posted in LinkedIn on June 6, 2016]
A simple introduction - Part 1
A friend came up to me at work the other day, and said, "Hi Mr BIM, What is BIM?"
Let's take a straightforward, non technical, non PAS approach to answering that question, in a simple mind-dump style.
It is space for a RHS steel column. That column progressively becomes 305x305mm as the design progresses, and then has flanges at each end. The column gains surface treatment, fire retardant, and cosmetic cladding. The flanges then gain bolt holes, M20 bolts, washers, and nuts. All within the original space allocated. Each time the 3D object is pulled from a library full of objects at the appropriate level of detail. LOD. Design progresses though the digital plan of work from bright idea, to concept, to detailed design, and then on to construction, as-builds and finally into asset management.
The column is an asset, as are each of the bolts, and each of the nuts. Even the humble washer is an asset, with its own asset number. It is part of a system. The nut bolt and washers assembly are part of the system that joins two adjacent objects together. The column is another part of the system. The function of the column could be described as being the transfer of loads. The purpose could generally be described as to hold up the ceiling and all the other things above the top of the column. In certain parts of London, where the water table is rising it could be that it is pulling downward, stopping the structure floating. Either way it is transferring load, as part of a system.
As it is pulled into the design from the library it should be given a code. That code should be a matrix code which contains information about the object, the location, the system, the function, and the assets that constitute the object.
Is that all there is to BIM?
Is that all there is to BIM? Well, in a word, no.
When you pull that object from the library it will come with some predefined metadata. The column is RHS, rectangular hollow section, so it will have the dimensions of the section including the wall thickness and corner curvature profile. It could have the bending moment, elasticity, and type of steel. It will have the weight per metre. Knowing the type of steel will provide information about the amount of imbedded carbon in the material. Specifying the ratio of new to recycled steel will provide information about the imbedded carbon in the manufacturing process. We can start to measure carbon content. We will have to wait until later in the process to add another element of metadata, where in the world the steel is manufactured and how it is transported to the construction site. The metadata can hold all the core data about the object. Links attached to the object can include COSHH data, maintenance information, inspection regime, and demolition/recycling facts. Design, construction, operation, replacement, and decommissioning risks and hazards can also be attached. This is one object in a BIM Model with the three elements, documentation, non-graphical information and graphical information, all in a digital interconnected form. Further objects are dragged from the object library and connected to the same system until it becomes the model of the structural steel frame of a building, either proposed or existing.
With all of the digital data being integrated and intelligent it is a simple process to change something.
All of the objects together in the 3D model can be visualised and presented to stakeholders in various mediums ranging from simple isometric views for a exhibition or consultation, to a rotating 3D screen view, perhaps with walk through, on to a fully immersive augmented reality using specialist goggles. Early days yet, as only at steel frame stage.
The model has been transferred to the client from the structural designer within the common data environment. The shared digital space which is the single source of truth for all of the collaborating parties across the whole spectrum of the supply chain. The client decides that he wants to increase the floor to ceiling height of the reception area by 50% more. Easy, select the relevant columns and stretch them. All the associated dimensions change and all of the connection and connected elements move with it. The new design is reanalysed. Then, because the BIM objects have 4D and 5D elements attached to them, all at appropriate levels of estimation based on the LOD, the client can instantly be advised of the cost and time implications of his decisions. The client can then make an informed decision to proceed with the change, revert to the previous, or try something different. Information based decision making. The concept of designing to a predetermined budget becomes a reality.
One system is in place, generally created within one discipline. Now we can start with the other systems.
However, let us return to space before we go there. Earlier we mentioned the space for the column. Understanding space is really important. After all, it is space that you are creating when you design a building. Space for desks, homes, or machinery. If it is not a building but a railway tunnel, it is space for a train. Not just a static train but one travelling at speed, with the inherent wobbling from side to side, and bouncing up and down on the suspension. The kinematic envelope. That is just one space in the tunnel. Add the space for the pantograph and overhead line equipment (OHLE). As recently done in the 175 year old Box Tunnel. Line speed of 125mph, but not enough space to add electrification without lowering the invert of the tunnel and thereby the track. Back to the design of the tunnel. Space is required for linear systems such as track, drainage, and cables and discrete items such as signs and signals. All of these space allocations define the internal diameter of the tunnel. Add the wall thickness based on the geology and loadings, and you have the diameter of the TBM. Going back to a building, you define the amount of space you require, the use of that space, and the quality of the building and finishes. The building is merely a facilitator of the space required. Infrastructure is the same, irrespective of whether the space is for cars, trains, water, or gas. Having understood that it is much easier to understand the importance of starting your initial BIM model with spaces, sometimes called volumes.
Now back to the structural frame. The structural frame is outlined to create the space required. That does not mean that it is fixed and unchangeable. All the other systems collaborate to define their space requirements. Notice that disciplines are being generally avoided as this just perpetuates the problematical concept of silos. Silos must be broken down to facilitate collaboration. BIM at this stage requires a space manager. A controller of all the spaces and the arbiter of the disputes, sorry, discussions about one space encroaching on another. The space allocation for the air conditioning duct has to include room to fix it and to maintain and replace it. The design develops and the duct size has to increase. This impacts upon adjacent spaces. The space manager resolves the reallocation in collaboration with all of the relevant stakeholders, including the structural frame if necessary. Again the time and cost consequences can be considered as part of the resolution. Numerous 'what-if' scenarios can be run to optimise the decision. Each object, including the column has to fit in its allocated space which ultimately provides the required free space. Each system is developed within the space for that system. Now comes the fun time. Joining all of the system designs together to form a federated model. All of the previous provides clash avoidance, but still run the clash detection just to check.
Surveying is at the beginning of the process
Is that the extent of BIM? No, that is just the beginning.
We have forgotten surveying. Well, is that is excusable, as it is quite common? No, it is not. Surveying is at the beginning of the process. Unless, you are a retail tin shed provider, where the design is the same irrespective of the site. Or perhaps a housing developer where you have a set number of standard designs, including of course some for so called affordable housing.
Sorry, time for the interlude. A developer has an interest in making a profit. He has a plot of land which will provide a profit of X giving a return on investment of Y%. Then he is told that 10% of the proposed homes have to be affordable. This translates to below cost. The developer can either subsidise the community or more likely just put up the price of the other homes thereby maintaining his X and Y. This increases the gap between open market and affordability. Increase the requirement to 20%, this only exasperates the effect, making the gap even bigger. It does not take a lot to extrapolate the curve to understand that this is an unsustainable and failed initiative. Social housing is a good thing but should be provided by the whole community for the benefit of the community. Paid for by taxes, not an indirect hidden tax on development which artificially increases the cost of new housing, thereby pulling up the cost of the whole housing stock. Tempted to have a rant about right to buy Housing Association properties. Another ill conceived illogical idea. End of interlude.
Surveying has moved on from being a couple of guys with a 20" theodolite and staff, or a dumpy level. Information is a lot quicker and cheaper these days. Start with a LIDAR and photogrammetry survey in HD. It takes a little longer and costs a little more but will save resurveying later in the process. Overkill for feasibility but sufficient for design in one hit. I know some people say only get the information that you need at the time. However I consider it to be more efficient to get as much raw data as you can and only process as much as you need. Then when you want a little more to the left you don't have to send out a team again, perhaps to a position of danger, you just pick out the raw data and process it. Surveying has become sexy again. Not in the rugged explorers surveying mountainous terrain way, and creating the first OS maps for our delight and information. Now we have GPS, satellite images, fixed wing and helicopter aerial LIDAR, drones, and cluster autonomous AI drones and bots. Spatially targeted communication, air to ground swarm bots. All for the things we can see, and a multitude of ground penetrating radar and wall penetrating radar for the things we can't see. A couple of years ago BIM would have been considered a swear word at a GIS meeting, now they are getting into bed together. Geoenable BIM is the thing of the moment. It significantly enhances and augments standalone BIM. Geographical Information Systems, GIS, brings a wealth of other data once the BIM model is GEO located. That location can be http://what3words.com OS grid, London grid, or Latitude and Longitude. GIS is a system designed to capture, store, manipulate, analyse, manage, and present all types of spatial or geographical data. A standalone BIM model can be given an aspect, but with a location it can both get data for Smart Cities and as an as-built, give back to Smart Cities. Types of information includes tides, flood risk, weather, pollution, air-quality, traffic, solar impact, Climate Change, insurance premiums, retail demographic, objection demographic, area demographic, all as both current and projections. Utilities, Underground railways, mines, and in London, a 3D geology map all add information to the BIM model which aids the decision making progress. Designs become better, with less uncertainty, which equates to less cost, better return on investment. Having the BIM model associated to it’s surroundings helps with planning permissions and providing information to stakeholders in a intelligible manner.
That leads us into informatics, but that is another discussion.
Perhaps that is enough about early digital plan phase BIM. There is of course process, technology, and codification, as well as people.
The required processes
The required processes are well documented but even these can be progressively implemented as your BIM understanding increases.
Technology is another primary element
Technology is another primary element of BIM and is both software and hardware. What you can do in the software and associated software systems such as GIS, Internet of Things, Big Data, and Smart Cities, to name a few is alluded to above. Hardware for the Common Data Environment can be on local servers or in the cloud. It should be owned or controlled by the Client. It is the Client’s data, before, during, and after the intervention (Project). If the Client is not confident in running and maintaining the CDE, he could employ an independent to run it for him. Somebody separate from the Project team. Proprietary Software is a matter of choice, based on best for the job. An informed client will not want to specify the BIM software to be utilised by the supply chain, and will remain software agnostic. Any course other than this negates the open concept of BIM and leads to inefficiencies within the supply chain which will probably cost more than the savings achieved by the Client by just allowing one BIM design platform, and it is not exactly working together with the Project team.
Codification is very complex
Codification is very complex. On the basic level the code can by structured for the single intervention. This is the simplest solution and is an OK place to start. Even at this level the codes still have to relate to the rates database to provide cost data (5D) and to the WBS of the plan/schedule to translate to the time data (4D). However, this is very isolationist, and ultimately inefficient. The next level may be at enterprise level. This will also present problems if the organisation is large and regional. Nomenclature comes into play. Not only are there different regional names for the same items there are different definitions of similar things. When is a bridge a bridge, or a culvert, or a viaduct? How do you count the spans? Do you define the bridge by what is above or below it, or is this just metadata? All such dilemmas have to be resolved to form a consistent codification. Then there are all of the legacy databases which have to be considered, and ultimately converted into the common codification. So a gargantuan task just to achieve enterprise level commonality. Don’t stop your BIM initiative to wait for the enterprise wide codification, you will loose out on too much learning and potential savings. BIM implementation is not linear. It should be approached as a parallel, concurrent collection of activities. In the process of developing your enterprise solution consider the wider national and international structures available such as Uniclass 2015. These are still in development so are likely to change. Again, don’t be diverted or discouraged by this difficulty. Consider if your codification can just be regenerated by mapping one digital data to another when the other structures are resolved. Then you will have the ability to constantly compare your intervention with similar ones across the world. Enabling both national and international benchmarking.
Importantly on to People
Importantly on to People. People are both the most important part of BIM and the most challenging part at the same time. It is people who chose to use the tools and processes or not. As a company you can tell people what to do, but that is only effective to an extent. I have heard expressed a view that people are not a significant element to BIM. They will do as they are told. I don’t prescribe to that view. It takes a lot of time and effort to change the direction of the company. The strategy and mission statement have to be reviewed. Perhaps even the business model. Then you need to start a process of engaging with the staff to commence a structured culture change process, which includes a communication strategy. The different tools and processes are only part of the learning. There is also the required change in behaviours. Behaviour is the real key to collaboration. You can put collaboration into a contract and have KPIs but that does not in itself engender the real collaboration that is required. The Client’s team has to be well versed in the ideas and practices of collaboration, and as with many other things, show leadership and direction. The Client’s team need to embrace change and innovation. Embrace collaboration and live the collaboration dream to deliver the expected results. Then the supply chain teams can get on board and really work this collaboration thing. The supply chain does not follow suit by osmosis alone though. Those companies have to make the same level of investment in their people, including the initial navel gazing. The corporate and cultural change throughout the supply change is the most important element of BIM, the most difficult to achieve, and the longest to come to fruition. Normal change management would be to not start banging the drum until you have something to teach. Don't start teaching until you have something to work with. Teach somebody some new software and if they don’t have access, time, and need to use it, within three months they will need retraining. However, whilst the rules still apply to BIM, treat it as part of the engagement phase, another aspect of communication. There is a lot to do in as short a time as possible and this is the part of BIM implementation that will cost money. Don't delay until you have all the answers. Find ways to engage with your people, to get them interested in change and innovation. Help them to understand what BIM is and how it will effect almost every one in the industry in some way or another. Unless you are about to retire BIM will affect you!
Unless you are about to retire BIM will affect you!
More on the later stages, in another article.
BIM is many things to many people and it is still evolving. No single explanation will suit all, but one thing is sure, BIM is change. Change to attitudes, change to working practices, contracting, procurement, perhaps even change is required in the EU Procurement Rules. Change to business models and of course to technology. We as an industry should look at how we can reduce the number and height of walls as the data progresses from conception to operation and decommissioning.
BIM is the glue. BIM is transformational.