In 1957 he was elected as an honorary member of the International Federation for Information and Documentation (FID) and was made vice-president for life of the Library Association of Great Britain.

Among the 900 applicants for the position, none had any formal training in librarianship, and Ranganathan's handful of papers satisfied the search committee's requirement that the candidate should have a research background.

[7] Ranganathan travelled to University College London, which at that time housed the only graduate degree program in library science in Britain.

At University College, he earned marks only slightly above average, but his mathematical background made him latch onto the problem of classification, a subject typically taught by rote in library programs of the time.

To Ranganathan, a structured, step-by-step system acknowledging each facet of the topic of the work was preferable to the "intellectual laziness" (as he termed it) of the DDC.

He began drafting the system that would ultimately become colon classification while in England, and refined it as he returned home, even reordering the ship's library on his voyage back to India.

[11] Ranganathan sought to institute massive changes to the library system and to write about such things as open access and education for all.

When writing about the harmful effects of low budget on the good functioning of a library, Ranganathan described it as "making an Ulster of the ... law of parsimony.

"[citation needed] After two decades of serving as librarian at Madras – a post he had intended to keep until his retirement –, Ranganathan resigned from his position at the age of 54 after conflicts with a new university vice-chancellor.

After a brief bout with depression, he accepted a professorship in library science at Banaras Hindu University in Varanasi, his last formal academic position, in August 1945.

He held an honourary professorship at Delhi University from 1949 to 1955 and helped build that institution's library science programs with Surendranath Dasgupta, a former student of his.

Ranganathan established the Documentation Research and Training Centre of the Indian Statistical Institute in Bangalore in 1962, where he served as honorary director for five years.

Ranganathan dedicated his book The Five Laws of Library Science to his maths tutor at Madras Christian College, Edward Burns Ross.