Professinal program accreditation is a rigorous, resource intensive and lengthy process. The accrediting agency, ABET for engineering, has a series of program standards that the college has to meet. Standards in terms of course work, faculty qualifications, computers for studet use, course work to include some type of capstone course for design for engineers, etc are all required. The college integrates all of these standards into their programs, with each standard woven in the course work. Here is an example-- today, industry wants new graduates to have experience in oral and written communications. The standard will say something like that. The program and various courses will then require that in a specific class that the student has to make an oral and written report during the course of the term in that class.
Another example is team work. The standard may address the ability of the graduate to work in multi disciplinary, multi cultural teams. OK, so the College Dean, Department Head and individual course professors then develop courses where the student works in a team. The senior capstone or design course is usually used for this in engineering. When I was a Business Dean, we used a capstone business plan course to fulfill this standard.
The College attempts to achieve these standards for the period of the accreditation, normally 5 years. If the program is accredited, in the 3rd year, the college begins what is called a self study, identifying all the good and bad parts of their program. This normally takes one academic year to prepare and complete. When this is completed, the self study is turned into the professional accrediting body, ABET for engineering. This document, normally 2-3 big 3 ring binders is then reviewed by an accreditation review committee, normally other college Deans and sometimes senior faculty members.
During the 5th year of accreditation, this review team comes and visits the campus for 3-4 days, talks to the administration, faculty, students, employers, alumni to see if what is documented and said in the self study is indeed factual. If it is, they then caucus after they leave the campus visit and prepare a final adjudication report. This report is normally considered "Draft" until the annual meeting of the accrediting body, ABET in this case. At the annual meeting, this report is presented and voted on by the members present. If successful, the program is re accredited and the 5 year clock begins anew!
ABET is comprised of members of all of the professional discipline societies-- IIE, ASME, etc.
Hope that this explains the question better!