BIM时代伊始，人们认为单独的一个应用程序就能满足所有层面上的需求：作为工具、作为平台以及作为环境。随着人们理解了BIM项目的体量和支持应用程序的系统，这种理想主义便慢慢地减弱了。用于全局支持高级BIM项目的一个重要能力是在一个多重平台和多重表现的环境中支持工作。一个BIM环境要有生成和储存构件实例以用于不同工具和平台并能高效管理数据的能力，包括在构件级别的变更管理。第三章的第3.5节着重讨论了这方面。这一点可通过任何时候修改项目而发生更新的变更小旗和时间戳来处理。目的是转换和管理构件以及构件集而不是文件。

接下来我们概述了主流建筑模型生成平台的最新功能。有些平台仅支持建筑设计功能，另一些只支持各种类型的加工级别的建筑系统，还有一些平台在这两方面都能支持。下述每个评估都是针对所述软件系统的版本；后续的版本可能会有更好或者更糟的功能。我们根据之前所述的准则来审视这些平台。

BIM平台能以多种方式用于建筑建设：例如建筑师用它来设计模型并出图，工程师用它做结构或者能源数据管理，承包商用它来做施工协调模型、加工深化或设施管理；他们包含了不同类型的工具功能。有些平台的市场定位于多类型用户。不同的营销战略导致软件安装包中不同的功能集合。在此，我们不去解决这些不同的用处，而是从平台的主要产品的角度，并参照其它在同类平台上运行的其它产品来考量主要的BIM平台。他们的应用与局限会在后面与不同类型的BIM用户相关的章节中明确阐述。我们从第2.3节（回复B32查看）中所述的三个层面考量每一种平台：作为工具、作为平台、作为环境。

众所周知，获取软件安装包非常不同于大多数其他采购。虽然采购汽车是基于非常具体的产品和属性组，而软件安装包同时包括其最新功能以及定期发布（至少每年发布）的增强功能的开发路径。购买者买的既有当前最新的产品也有软件公司对其产品未来的发展计划。购买产品的人也是在购买该公司内至少一人将会使用的支持系统。该支持系统是对用户提供的文档的增强也是嵌置在BIM工具中的在线支持。除了供应商的支持网络，软件持有者也是更广泛用户社区的一部分。大多数平台提供了博客沟通用于点对点帮助和用于构件族转换的开放门户。这些可能是免费的或低成本的。在获取BIM平台时，也应该将这些考虑进去。

At the beginning of the BIM age, it was thought that a single application could serve the needs at all three levels: as a tool, as a platform, and as an environ- ment. That idealism has slowly waned, as the scale of a BIM project and the systems to support it have become understood. An important capability needed to globally support advanced BIM projects is to support work in a multiplat- form and multipresentation environment. A BIM environment needs the ability to generate and store object instances for different tools and platforms and to manage that data effectively, including change management at the object level. This issue is addressed more centrally in Chapter 3, Section 3.5. This can be handled by a change flag or a timestamp that gets updated whenever an object is modified. The goal is to exchange and manage objects and sets of objects rather than files.

Below we offer an overview of the current capabilities of the major building model generation platforms. Some reviewed support only architectural design functions, others only various types of fabrication-level building systems, and others both. Each assessment is for the version of the software system noted; later versions may have better or worse capabilities. We review them according to the criteria developed  above.

BIM platforms may be used in diverse ways in building construction: by the architect for design modeling and drawing production, by an engineer for structural or energy data management, by a contractor for developing a construction coordination model, for fabrication detailing or for facility management, for example; they include varying types of tool functionality. Some are marketed to multiple types of user. The different marketing strategies lead to packages with different collections of functionality. In this review, we do not address these different uses but consider the major BIM platforms generically, from the perspective of its primary product, with references to other products running on the same platform. Their uses and limitations will be considered more explicitly in the chapters associated with the different types of BIM users. We consider each platform from the three levels outlined in Section 2.3: as a tool, as a platform, and as an   environment.

As is broadly understood, the acquisition of a software package is very dif- ferent from most other purchases we make. Whereas the purchase of a car is based on a very specific product and set of features, a software package involves both its current capabilities and the development path of enhancements that are released regularly, at least annually. A purchaser is buying into both the current product and its future evolutions, as projected by the company. One is also purchasing a support system that at least one person in a firm will be dealing with. The support system is an augmentation of the user-provided documentation and online support built into the BIM tool. Apart from the vendor’s support network, a software system owner is also part of a broader user community. Most provide blog communication for peer-to-peer help and open portals for the exchange of object families. These may be free or available at a small cost. These also should be considered in the acquisition of a BIM platform.