A Google Books search for "on-premise inspection" finds a dozen unique matches for that particular phrase, going back to at least 1955. All appear to be from the United States, and many occur in federal government regulations. Unfortunately the dating on such published regulations (which may be revised multiple times) is extremely misleading, and in some cases the matches are shown in snippet view, so there is no way to confirm the actual date of origin of many of the matches.
Here are a few examples from the Google Books search. From The Code of Federal Regulations of the United States of America, volume 7 (revised in 1955):
§989.158 Inspection of raisins on dehydrator's premises—(1) Application and agreement for dehydrator on-premise inspection, (i) Any dehydrator may submit to the committee for approval, and the committee may approve, in accordance with the provisions of this paragraph an application and agreement, on a form furnished by the committee, for dehydrator on-premise inspection of natural condition raisins produced by the dehydrator by subjecting raisins variety grapes to artificial heat.
From The Federal Reporter, Second Series, volume 398 (1969[?]):
72(2). — Acts constituting, and sufficiency in general.
Ct.Cl. 1968. "Plan for the Inspection Job" which continued off-premise inspection as originally instituted, rather than on-premise inspection as called for by supply contracts, did not constitute an agreement modifying the contract specifications to establish a single contractually specified inspection procedure.—Red Circle Corp. v. U. S., 398 F.2d 836.
From U.S. General Accounting Office, "Alcohol and Tobacco Excise Taxes: Laws and Audits Need Modernizing" (1977):
Our review has shown that the on-premise inspection system in the distilled spirits and industrial alcohol industry results in an unnecessary expenditure of resources to insure proper payment of excise taxes. The review has also shown that an inordinate amount of staff-time is expended in beer, wine, and tobacco inspections while only negligible monetary results in terms of tax deficiencies are found.
From Bill Rodgers, "Pesticide Safety - Standard Operating Procedures," in Proceedings of Seminar/Workshop on Tick Eradication Measures (September 3–6, 1985):
- Spraying Livestock with The Spray-Dip Machine
a. When spraying livestock with the spray-dip machine, the guidelines in VS Memorandum 556.5 should be followed.
b. An on premise inspection should be made by the supervisor, or inspector in charge of the spraying operation, to see that suitable facilities are available to do a safe and effective job.
From a translation of "Anti-Monopoly Law of the People's Republic of China" (August 30, 2007) in Anti-Monopoly Law and Practice in China (2011):
When investigating suspected monopoly conduct, the AMEA [Anti-Monopoly Enforcement Authority] can take the following measures:
(1) Conduct on premise inspection of the place of business of the undertakings under investigation or other relevant places,
(2) Question the undertaking under investigation, interested parties, and other relevant organizations and individuals, requiring them to provide relevant information;
These examples suggest that "on-premise/on premise" has been in use in U.S. government publications for at least 60 years. In the past 30 years or so—and especially in the past decade— references to real-estate property and fixtures as "a premise" or "the premise" rather than as "premises" or "the premises" have become much more common, in and outside government texts.
As I note in answer to the related question Is "premises" referring to a single property considered a plural noun? Google Books searches turn up multiple matches for various phrases such as "enter the premise," "search the premise," and "allowed on the premise"—where premise refers to land, a house or other structure, and/or other property—suggesting that increasingly in actual U.S. practice people are flouting the traditional rule that plural premises is the correct form to use in such cases.
As prescriptivists we may regret this development, but as descriptivists we need to take seriously the evidence that the old idea that premise[s]-as-property is always plural no longer reflects reality.