The objective of the present paper is to find methods necessary to compose a general text processing system by analysing software system, `FORMAT``(developed at SCAC) and running test programs desinged for testing as many feature in `FORMAT`` as possible. The explanations given included a general program flow which varies significantly according to each feature, and concrete internal paths and methods of handling FORMAT``s facilities, e.g., ones for the frequency dicitionary and locating text words in the input streams.