IGES (Initial Graphic Exchange Specification) is initially a CAD vendor-neutral exchange format for 2D/3D data exchange. A plenty of CAD/CAM systems are using it to provide the digital exchange.
The official title of IGES is Digital Representation for Communication of Product Definition Data, first published in January, 1980 by the U.S. National Bureau of Standards as NBSIR 80-1978. Many documents (like early versions of the Defense Standards MIL-PRF-28000 and MIL-STD-1840) referred to it as ASME Y14.26M, the designation of the ANSI committee that approved IGES Version 1.0.
Using IGES, a CAD user can exchange product data models in the form of circuit diagrams, wireframe, freeform surface or solid modeling representations. Applications supported by IGES include traditional engineering drawings, models for analysis, and other manufacturing functions.
The chief advantage of IGES is that it is unencumbered by licensing, i.e. it’s cheap as free. Which is probably why it’s still everywhere after all these years. But all meaningful development of IGES stopped in 1996 at version 5.3.
As you see IGES is quite old and abandoned. It wasn’t updating since 1996 and nowadays it might give you an unexpected results during your work. At first, IGES has a weak solids capability, mostly because solids came to this format too late. It also doesn’t support product structure. It means you are not able to keep the assembly structure in IGES.
At a shrewd guess, i’d say that IGES is an rusty neutral format. Due to its old age, it may need to be retired.
IGES files often require time-consuming repair or complete remodeling. As the 2013 State of 3D Collaboration and Interoperability Report noted, nearly 50% of engineers spend over four hours a week fixing design data; it is easy to see how so much time spent repairing models could throw off the production schedule.
Generally speaking, anyone using IGES today should be doing so because they have no other options. Those who must deal with IGES files should make sure they have the in-house tools to make geometry repairs (such as removing duplicate vertices, zero area faces, and extending and reintersecting faces) and are able to sew the various surfaces into a watertight solid. Additionally, users should have the tools to translate watertight solids into more viable formats, such as Parasolid, SAT, JT, CATIA, STEP, etc.