i-model Primer

Introduction

Fundamental to the success of any infrastructure project is information, and how that information is created, shared, distributed, delivered and applied. Yet, design teams must execute each project with an information-technology environment that includes a host of software applications from several vendors, each with differing information models and file formats. As a result, a significant amount of manual effort is often times involved with the distribution and sharing of information. This can be particularly problematic when information must flow across functional, organizational and lifecycle phase boundaries.

Systems which attempt to address interoperability using a monolithic, centralized approach are incompatible with the dynamic and inherent uniqueness of each project. Point-to-point information sharing between applications seldom goes beyond importing and exporting file formats and do not scale. Having an interoperable platform that acknowledges and embraces the dynamics and uniqueness of every infrastructure project; commits to supporting current and future standards; and provides the opportunity to further leverage project information, allows project teams to execute more effectively and increases the return on information technology investments.

Bentley Systems offers such an approach through its interoperability platform. Based on a federation strategy, it enables infrastructure projects to achieve interoperations among its information technology systems by creating an interoperable project environment. The platform includes the following key characteristics:

• Embraces existing applications.

  • Offers an increasing array of off-the-shelf connectors, which enable heterogeneous information sources to connect to the interoperable project environment.
  • Software toolkits make it possible to create new connectors for additional information sources.
  • Each source requires only a single connector, regardless of the number of other applications connected to the interoperable project environment.

• Synchronizes project information.

  • Information can be synchronized across multiple applications, ensuring that all applications appropriately reflect the current status of shared information.
  • Information can be aggregated, transformed and distributed to other applications and systems based on project rules.
  • Schema and the mappings between schemas are maintained externally to the application software, where they can be dynamically adjusted to adapt to changing project conditions and configurations.

• Generates integrated views of project information.

  • Can aggregate and transform project information into integrated "views" of the current project state that span multiple applications and information sources.
  • Project teams achieve this without resorting to inflexible or impractical solutions, such as a centralized database.
  • These views provide increased visibility into the project and a strategic value that is impractical or impossible to obtain with other approaches.

• Create dynamic deliverables.

  • Based on the integrated views into the project, the interoperability platform can create dynamic deliverables in a variety of forms and formats.
  • These dynamic deliverables are provided in multiple formats ranging from integrated intelligent models and drawings, industry standards such as ISO 15925, intelligent web streams, intelligent publishing formats like PDF and intelligent paper deliverable.

• Provides powerful client applications for extracting value from project information.
  • Provides a robust set of client applications (thick clients, web clients, information portals) to consume the dynamic deliverables.
  • Also provides a robust set of tools to create new applications that extend beyond visualizing and commenting on project information.
  • This expanding array of applications can be used for design review, analyzing the state/status of project execution, integrated project deliverables, construction, operations work orders, and multiple types of analysis, including safety, performance, and security, among others.
  • The applications "consuming" the dynamic deliverables can include those that provide feedback (e.g., redlines) to the content creators, as well as those that use the dynamic deliverables as the starting point for the creation of new content.

i-models play a central role within Bentley's interoperability strategy and are the currency for information exchange.

What is an i-model?

An i-model is a immutable container for rich multi-discipline information published from known sources in a known state at a known time.

• An i-model is a published rendition in a secure read-only container.
• An i-model is a portable, self-describing and semantically rich data file.
• An i-model is an interoperable deliverable tailored for change management.
• An i-model enables information exchange for all phases of a project lifecycle.

When are i-models used?

Examples of when i-models are used include:

• Whenever rich project information needs to be exchanged.

  • Between all types of products, including Bentley and 3rd party applications.

• Whenever project information needs to be reviewed at a particular project milestone.

  • Dynamic review is an example.

• Whenever change management is important.

  • Particularly when iterative delivery is required.

• Whenever flexibility is required because project information is expected to be re-used in a variety of ways.
  • Supports "publish for purpose" workflows.

What are the benefits of an i-model?

The characteristics that make an i-model ideal for project information exchange:

• Secure, self-describing and portable.

  • Read-only, immutable containers.
  • Do not require special application logic to process them.
  • Schema independent, which enables support of industry standards.

• Published from known sources in a known state at a known time.

  • Published renditions wrapped in an immutable container.
  • Origins and history can be traced via provenance.
  • May contain version and change delta information.
  • Ideal deliverables for iterative workflows that require management of change.

• Flexible, interoperable, designed for information re-use.
  • The level of richness for graphics, properties and relationships is configurable.
  • Multi-discipline content can be aggregated and stored in an i-model.
  • Can be re-published into standard formats like PDF and XML.
  • Can even be rich enough to be repurposed into new source content.

What are the characteristics of an i.dgn?

When an i-model is persisted in a DGN container it inherits all of the characteristics described above. Some more detail on DGN i-models:

• Always has a file extension of i.dgn.
• Has an internal property that indicates it is an i-model.
• Graphical data are stored as known DGN element types. Business data are stored as ECXAttributes.
• Resources like references, schema and custom icons used when browsing instances are embedded.
• References to external content are represented in standard, well-known mechanisms.
• Read-only by way of DGN file protection. Added security can be applied using digital rights.
• Traces the provenance of the file and its models.