Thanks to the rise of cloud computing and web-based software, firms in the AEC sectors are facing even more complex decisions in how to deploy traditional desktop software for mission-critical design and construction projects.

Autodesk, for example, is releasing more web-based versions of its traditional desktop tools and offering cloud-based options for renting as many core processors as a project may require. During an investor conference on Oct. 2, the firm announced that, starting in 2015, most customers will not be able to purchase software upgrades in the traditional mold.

The move comes as Autodesk joins other AEC vendors that are shifting from a perpetual license model that includes annual upgrade fees to various subscription models. Most new business models involve more ways to rent desktop software systems.

Andrew Anagnost, Autodesk senior vice president for industry strategy and marketing, said, "Maintenance subscription is the best way to stay current on applications." Design firms and other AEC customers are seeing the spread between the perpetual software price and the rental price and see a way to lower up-front costs of adopting the tools, he noted.

In addition to offering desktop rentals for its products, Autodesk plans even more cloud-based tools that complement its BIM 360 tool sets that provide web-based delivery of tools that were once marooned on a desktop.

Other AEC software vendors are offering more alternative provisioning options, taking advantage of subscription delivery capabilities and web-based tools.

In addition to its traditional products, Bentley Systems, Exton, Pa., a major BIM and project-tool provider, is expanding its licensing models, launching more modules that address specific projects. Since 2011, Bentley has offered portfolio balancing, in which customers can exchange underused Bentley software for other products. The company calls it a "sustainable licensing" business model.

AEC firms have hard choices ahead, and more options to choose from.