LabLENI (Valencia, Spain)




Ministerio de Economía y Competitividad


3D CAD annotations management to improve the design process on industrial and architectural environments.

Industrial and architectural product quality is largely conditioned by the quality models and the communication flows of the design process. ANNOTA explores the use of 3D annotations in this context, manufacturing and architecture industry, providing innovative use of model annotations between different actors involved in the process of designing and manufacturing new products. ANNOTA will test the hypothesis that the 3D semantic annotations can improve the CAD model quality through several field studies, by applying quality metrics. It also will explore the impact of the annotated models in collaborative engineering environments and it will evaluate new proposals for technical training with 3D CAD models as a mean to facilitate the training content.

This project is funded by the Ministry of Economy Competitiveness within the State Program of Research, Development and Innovation Oriented
Challenges of the Society in the State Plan of Scientific and Technical Research and Innovation 2013-2016 file number TIN2013-46036-C3-1-R “.

Model-Based Enterprise concept (MBE) emerged in the United States since 2010, sponsored by the National Institute for Standards and Technology (NIST) through an annual “summit” on this topic ( The MBE concept is based on the exploitation of Model-Based Definition concept (MBD) which integrates a data set, consisting mainly of the 3D model geometry and a set of annotations. The annotations provide information and support to the manufacturing life cycle and may contain notes and lists. The MBD provides a complete digital product definition, without additional features such as 2D drawings documents because annotations are connected directly to the model geometric elements and are organized appropriately without interfering with it.

All this is provided by standards such as ASME Y14.41 and ISO 16792 which support rules for establishing logical associations between product information and geometric elements with the aim of generating comprehensive and reusable annotated models. Most of the commercial CAD systems support these standards through modules and Product Manufacture Information (PMI). These modules provide tools to: handlieannotations, define and select annotation planes, manage data visibility and metadata, and creatie dimensions and tolerances within the own 3D model.

In general, an annotation is defined as a comment or text block which is added to a 3D object. In CAD context, a notation refers to additional information, in any format (text, image, audio, and video), which is inserted into a CAD model and connects to a specific geometric element.

Ding and other categorized annotations into six different groups (each of them with their respective subgroups) according to various criteria: type of audience, type of communication, representation system, use and function, display and storage. They also identified three major gaps in current annotation technologies:

  1.  The anchoring annotation mechanism: junction between the annotation and the geometric CAD model element being annotated.
  2. The annotation content representation: which must contain a notation and format.
  3. The annotation interface: used to insert and retrieve annotations.

A further classification takes into account where is storaged the information, distinguishing two types of entries: “in-line” (in the own CAD model) and “stand-off” (in an independent external repository).

Different studies propose the use of the original CAD model, or a light derived representation (lightweight) as key element to gather information generated by users along the different product life cycle stages. The authors apply a “stand-off” approach using external XML files and using an external application (no interaction with the PMI module) to connect the annotations to specific geometric elements in the CAD model.

The system limitations include difficulties in maintaining updated annotations when the model changes (“name persistence problem”) and data connected to the model management to efficiently perform processing operations and information retrieval. Others suggest the use of CAD models as carriers of knowledge following a purely approach “in-line”. In their study, the authors incorporate all the knowledge related to the product within the CAD model. To show his technique, the authors developed a software prototype to introduce annotatuions in the PMI module of a Siemens NX CAD system. However, there are no references to any tools for searching and retrieving information in its implementation. To distribute the annotated models to other people, the authors used Acrobat 3D formats and JT.

ANNOTA aims to take advantage of MBE and the availability of PMI modules in commercial CAD tools to add value to the use of this infrastructure to improve collaborative design processes. Previously other researchers have worked on different areas related with the use of 3D CAD annotation systems, defining strategies of processes design knowledge management and modeling strategies aimed to improve CAD model quality.