When discussing BIM diffusion within an organization (micro) or across a whole market (macro), two terms typically pop-up: top-down and bottom up.
TOP-DOWN diffusion is a push by an authority to mandate the adoption of a specific solution it perceives as favourable. A good example of a macro top-down BIM dynamic is UK’s BIM Level 21 mandate and Singapore’s rolling BIM submission milestones2. At the micro level, top-down diffusion occurs when senior management within an organization (irrespective of its size and location within the supply chain) mandates specific solutions to adopt. Through these - sometimes coercive - pressures, solutions start diffusing down the authority chain and – if coupled with education and incentives – are adopted.
BOTTOM-UP diffusion refers to the grass-root adoption of technologies, processes or policies without a coercive mandate. At the macro level, this occurs when small organizations or those near the bottom end of the authority/supply chain adopt an innovative solution or concept; the solution slowly becomes a common practice; and gradually diffuses up the supply/authority chain (as is the case in Australia). Similarly at the micro level, bottom-up diffusion occurs when employees near the bottom end of the authority chain introduce an innovative solution and – over time – this solution is acknowledged and then adopted by middle and senior management.
Although these two dynamics are easily noticeable, a third dynamic lies hiding in plain sight: the MIDDLE-OUT diffusion pattern.
Middle-out diffusion applies to all those organizations and individuals occupying the median space separating the ‘bottom’ from the ‘top’. At the micro organizational level, team managers, department heads and line managers push what they’ve personally adopted up and down the authority chain. At the macro market level, middle-out dynamic applies when mid-sized organizations (relative to the market – e.g. large contractors in the US) influence the adoption of smaller organizations down the supply chain. They also influence or actively encourage larger organizations, associations and authorities up the supply/authority chain to adopt and eventually standardise their solution.
Different organizations and markets display one dynamic more than the other due to a variety of market-driven3 and social variables4. However, top-down, bottom-up and middle-out diffusion dynamics are complementary and even mutually inclusive. It is a misconception that one dynamic can be better than the others. While there is some evidence that a top-down dynamic encourages faster adoption rates across an organization or a market, there’s no proof – BIMwash and twitter noise aside - that it leads to sustained infusion5 of BIM workflows and deliverables.
Think about this:
- Is BIM adoption within your organization top-down, bottom-up or middle-out?
- In your view, which one of the three dynamics is more effective at the macro scale?
 The term ‘BIM Level 2’ or ‘Maturity Level 2’ as based on the Bew-Richards model (2008) is actually a consensus-based milestone to guide and mandate staged BIM adoption across the UK industry. The use of the term ‘maturity’ is quite unfortunate as these levels have a rolling definition (e.g. what does Level 3 refer to?) and cannot be used to measure/qualify BIM capability within organizations.
 The Building and Construction Authority (BCA) has a number of rolling mandates covering BIM submissions. For example, July 2015 is identified as the milestone for mandatory BIM submission for architecture and engineering design of new building projects > 5000m2.
 Market variables include supply and demand, risks and rewards, and a variety of competitive pressures.
 Refer to isomorphic pressures (coercive, mimetic and normative pressures) - research conducted by DiMaggio and Powell (1983) and recently adapted for BIM by Cao, Li and Wang (2014):
DiMaggio, P. J., and Powell, W. W. (1983). “The iron cage revisited: Institutional isomorphism and collective rationality in organizational fields.” Am. Sociol. Rev., 48(2), 147–160
Cao, D., Li, H. and Wang, G. (2014) 'Impacts of Isomorphic Pressures on BIM Adoption in Construction Projects', Journal of Construction Engineering and Management and Cao, D., Li, H. and Wang, G. (2014) 'Impacts of Isomorphic Pressures on BIM Adoption in Construction Projects', Journal of Construction Engineering and Management,(preview published July 8, 2014).
 Accrding to Cooper and Zmud (1990), adoption is but the second stage of a six-stage diffusion process: initiation, adoption, adaptation, acceptance, routinization and infusion.
Cooper, R. B. and Zmud, R. W. (1990) 'Information Technology Implementation Research: A Technological Diffusion Approach', Management Science, 36(2), pp. 123-139.