1. The GTCM is one of many competency models.
The Dept of Labor has a whole bunch of models for different industries. I count 19 as write this; they range from Advanced Manufacturing (there is no basic manufacturing) to Water Sector. They all have that same pyramidal shape.
2. The GTCM defines GIS Technician workers' skills and competencies in the US.
Industry experts helped build it. Here’s the corresponding job description (which seems a bit dated to me based on the software products listed, but is a fine start).
3. The GTCM can be used by educators and trainers to develop course outlines and degrees/certificate programs that match these competencies.
It’s vendor and technology agnostic; that is, it's about skills, not specific software or hardware. There are some course outlines (including an open source software based one) from workshops done in 2011 by the GeoTech Center. You need a login/password to access them via a Moodle server.
4. There is a GTCM Assessment Tool.
The assessment tool is big spreadsheet that those with existing courses can use to see how their courses match the competencies. The assessment can then be used to enhance the course where there are weaknesses or confirm that topics missing in that course are covered in another course in a program.
5. The GTCM can ideally make it easier for business to hire qualified workers.
Since industry helps define the model, the argument is that schools (and other education providers) will address competencies in the model and thus graduate students who can tackle available jobs.
6. The GTCM can help in the creation of articulation agreements (agreements whereby schools accept each others credits).
For example, students who study GIS in high school may be able to transfer credit when joining a community college GIS certificate or degree program.
7. Industry organizations are beginning to use the GTCM as a basis for a variety of activities.
USGIF will be using the GTCM in its accreditation program for GEOINT (for schools, not for individuals) and GISCI is considering the addition of a competency-based examination aligned with the GTCM for its updated certification program. The GeoTech Center uses the model for a competition and URISA is looking into a management version of the model. (Source: Career One-Stop pdf)