After 21 years of letting the sources of its money shape its programs, the Metropolitan Washington Council of Governments (COG) is thinking about shifting that process into reverse.

COG directors last week authorized a review of the organization's accomplishments and a look at new directions it might take in the future. It will be a joint effort of COG's staff and its board, composed public officials from throughout the region.

In the process, observed Martha V. Pennino, A Faiffax County supervisor and COG president, the voluntary federation of 15 metropolitan cities and counties might be able to sharpen its blurred public image.

From a modest start in 1957 as a forum for discussing regional issues, COG has branched into a wide variety of progams. They range from coordinating land planning policies throughout the region to establishing and monitoring metropolitan air quality standards.

Various COG divisions deal with such diverse areas as public safety, transportation, water supply, governmental purchasing and manpower training.

Walter A. Scheiber, excutive director, told the COG board that many programs have resulted from emergencies or began "in response to what money was available from the fed." The latter remains a powerful influence.

For example, COG's Transportation Planning Board was created to carry out a continuing review of regional transport needs and construction progams that was mandated by federal law.

When COG began, it had a staff of two who occupied desks in a hallway at the District Building, Washington's city hall. Now it has 150 fulltime employes occupying suites in an office building at 1225 Connecticut Ave. NW.

COG's current budget is $6 million. Of that figure, 65 percent comes from the U.S. government, 20 percent from the states of Maryland and Virginia and 15 percent is contributed locally from city and country tax revenues.

Lorraine Mazer, Scheiber's executive assistant, proposed in a report that the COG staff should rate the organization's accomplishments by a method resembling a school report card. Similar methods could be used in ranking proposed future programs.

"Individuals or groups have often engaged in unusually dedicated efforts to formulate and justify projects that have not necessarily been related to their importance," Mazer's report declared.

Board reaction was favorable. "I think we definitely should do it," Mayor William E. Hanna Jr. of Rockville said of the proposed review. "We have strayed, there is no doubt in my mind that we have strayed."

Dickran Y. Hovsepian, president pro tem of the Montgomery County Council, voiced a cautionary note. There is a danger, he said, that the review could get so mired in detail that it becomes simply an exercise in paperwork.

Scheiber said the review would be done without adding to the COG budget.