The study reported was conducted at Concordia University after using the CAN/DOC ordering system to procure documents in the sciences directly from the Canada Institute for Scientific and Technical Information (CISTI) to assess the efficiency of interlibrary loan (ILL) procedures using this system. This study focuses on the relative turn-around times and costs of CAN/DOC and possible alternatives. Present ILL procedures are described, a detailed breakdown of the average delays and cancellations is given, and costs are analyzed. The costs of four alternative models for the ordering of requests available at CISTI are outlined. It is recommended that requests of scientific documents available at CISTI be ordered via Telex, with CAN/DOC used only in special circumstances, because of the 50 percent saving in cost per document ordered; that preference be given to ordering from CISTI over Quebec or Ontario university libraries because of the faster service provided by CISTI; that the use of CAN/OLE for document verification be continued; and that efforts be made to encourage CISTI ILL and government officials responsible for its operation to improve the interlibrary loan service. Data are presented in five appended tables. (RBF)