BIM – Beginnings of BIM

Adjunto en este artículo, un ensayo de William Mitchell, profesor de Arquitectura del MIT, en el que se realiza una reflexión sobre los orígenes del BIM (Building Information Modeling), con puntos clave cómo de donde sale el BIM y el cambio importante que ha supuesto en el proceso de diseño.

Se reflexiona sobre cómo la crisis económica del 2008, ha acabado en la arquitectura con la investigación formal de los arquitectos, y de cómo paralelamente, al mismo tiempo aparece la conciencia de que el modelado geométrico es una parte del proceso de diseño y construcción de un edificio. También la producción de muchos componentes es un proceso laborioso y costoso, sobre todo cuando los componentes son complejos y no son ensamblados de forma repetitiva. Unos cuantos pensadores pioneros, se realizaron la pregunta de si un nuevo software podría ayudar a dicha producción.

Las cadenas de suministro de los elementos del edificio son complejas y heterogéneas, estan dispersadas geográficamente y muchas de ellas se extienden a nivel mundial. Algunos procesos de fábrica son sencillos, otros son complicados, y todos ellos han de ser COORDINADOS para que las diferentes partes del edificio estuvieran en el momento adecuado en el lugar correcto. Estos sistemas BIM surgen en el siglo XXI para apoyar esta cadena de suministro de componentes del edificio.

Estos sistemas BIM no vinieron de la nada, sino que se basaron en la tecnología orientada a objetos. Se ha de tener en cuenta que desde hace mucho tiempo existen esfuerzos por ampliar las capacidades del sistema CAD de varias maneras – pasar de dibujos 2D a modelos tridimensionales, sustituyendo la geometría rígida con objetos basados en modelos paramétricos, y llegando a servicios cada vez más sofisticados para asociar propiedades no geométricas a las entidades geométricas, mediante la integración de un software de análisis de ingeniería, y apoyando el intercambio y la transferencia de información entre los distintos miembros del equipo de diseño y construcción. Pero los sistemas BIM pioneros intentaron realizar todo esto y mucho más, pero de una forma más integrada.

BIM supone un cambio muy importante dentro del proceso de diseño, ya que la actividad de diseño fundamental es la creación de familias paramétricas, QUE REQUIERE UNA COMPRESIÓN PROFUNDA DE LA ARQUITECTURA, DE LA TÉCNICA Y UNA INVERSIÓN DE TIEMPO CONSIDERABLE. Los diseñadores no tienen que limitarse a la única preocupación del diseño abstracto representada con los tradicionales dibujos, sino que puede llegar a la cadena de suministro (abre posibilidades a nuevos diseños y la responsabilidad aumenta). BIM genera expectativas de diseñar bajo los exigentes parámetros de rendimiento, coste y calendario.

ESSAY: THINKING IN BIM

William Mitchell, Professor of Architecture and Media Arts and Sciences at MIT

Beginnings of BIM

The global economic crash of 2008 probably marked the end of this twenty-year era of exuberant formal exploration. At around the same time, there was an increasingly urgent recognition that geometric modelling and component fabrication were only half story of making a building (or, for that matter, a physical scale model) – and maybe not the most challenging half. Fabricated components must also be delivered and assembled. Producing assemblies of large numbers of components is typically a laborious and costly process – particularly when the components are complex and assemblies are non-repetitive. A few pioneering thinkers began to ask whether new software tools, combined with digitally controlled assembly processes, might help with this.

This was a departure from the long-standing habit among architects of formulating building delivery issues in terms of simple dichotomies – of on-site construction versus prefabrication, and of craft versus industrial production. Now, increasingly, architects recognize that completed buildings result from complex, heterogeneous supply chains. These chains were geographically dispersed, and they often extended globally. Some of the processes that they encompassed were executed under precisely controlled factory conditions and others took place under difficult site conditions. Some were difficult and expensive while others were straightforward. Some involved significant uncertainty and risk. But all of them represented design opportunities and constraints, and all of them had to be organized and coordinated to bring the parts of a building together at the right time in the right place. The BIM systems that emerged in the early twenty-first century were intended to support this comprehensive, supply-chain-oriented view.

BIM systems didn’t come from nowhere. They drew upon the general technology of object-oriented computation. Furthermore, there had long been efforts to extend the capabilities of CAD systems in various ways – by shifting their emphasis from the construction and editing of two-dimensional drawings to the construction and maintenance of complete and consistent three-dimensional models, by replacing rigid geometry with object-based parametric models, by providing increasingly sophisticated facilities for associating non-geometric properties with geometric entities, by integrating engineering analysis software and by supporting sharing and transfer of information among the various members of design and construction teams. But the pioneering BIM systems attempted to do all this and a good deal more, in a carefully integrated way.

The assumptions and values embodied in BIM systems are clear and they imply some dramatic shifts in emphasis and strategy within design processes. Building up parametric object families – which can be both liberating and constraining to the design imagination – becomes a fundamental design activity, requiring deep architectural understanding, technical skill and considerable investment. The concerns of designers no longer need to be framed at the level of abstraction represented by traditional architectural drawings and geometric models, but can extend back down supply chains – a condition that both opens up new designs opportunities and increases responsibility. There is much greater opportunity to design to demanding performance, cost and schedule requirements and this generates expectations to do so.

All these do come at a cost. BIM systems are “Heavyweight” design environments, in stark contrast to the “Lightweight” pencil-and-paper environments that architects have employed for centuries. They can become cumbersome, constraining and inimical to free, creative exploration. Furthermore, the assumptions built into their operations and object classes can be difficult to identify clearly and subject to critical scrutiny. Central, ongoing challenges for BIM systems researches and developers are to provide abstractions and interfaces that can shield designers from the complex underlying apparatus where necessary, and to make built-in design assumptions clearly visible and subject to critical scrutiny.

BIM technologies and associated practices are gradually maturing. The term “Building Information Modeling” was first used, as far as I know, in the mid-1980s. Most of the necessary technologies were in place – at least in research contexts – by the late 1990s. A comprensive handbook, Chuck Eastman et al’s BIM Handbook: A guide to building Information Modeling, 2008 has appeared. Today, there is fierce competition among commercial BIM systems, an extensive field of ongoing BIM research, and a rapidly growing number of building design and construction projects are done, from beginning to end, with BIM systems.