Soviet leader Yuri Andropov today proposed changes in the Kremlin's strategy at home and abroad, saying many of the formally enshrined Communist Party policies "have not withstood in full measure the test of time."

Andropov, who was celebrating his 69th birthday, made the proposals at the final session of a two-day meeting of the policy-making Central Committee. The proposals, dealing with basic Soviet economic and political philosophy rather than specific actions, challenged some of the most deeply entrenched doctrines of the past two decades.

It was his most important speech since taking power in November and clearly placed Andropov's personal imprint on the party's thinking because it was approved unanimously by the 300-member body, according to an official communique.

The fact that the Central Committee decided to adopt Andropov's proposals suggests that his preeminence in the Kremlin is not being challenged, although the relatively few personnel changes in the top leadership announced today caused debates in the diplomatic community.

Some observers, while conceding that Andropov enjoys great personal authority, said his power was not sufficient to change the existing balance of power in the Politburo. Others, however, argued that Andropov may be interested in maintaining the image of continuity and that he was more concerned with policies than personalities.

The session of the Supreme Soviet, or parliament, on Thursday may shed additional light on the subject. It is due to elect a new president, a post vacated by the death of Leonid Brezhnev in November.

Andropov proposed modifications in the Communist Party program, which is the bible on Soviet strategy in domestic and foreign affairs, saying that it contains premature and unjustified provisions as well as "elements of separation from reality."

The current program was adopted in 1961 when Nikita Khrushchev boasted that the Soviet Union would "overtake" the United States by 1980. It was not changed by Brezhnev, Khrushchev's successor, although the last party congress appointed a commission to work on its modification.

Andropov's proposals suggested a more realistic and sophisticated approach. He reaffirmed Moscow's commitment to detente with the West despite an "unprecedented intensification of struggle between the two social systems." And he underscored that Moscow would not allow any shift in "the military strategic balance between socialism and imperialism" and that it would do "everything possible" to maintain its military might.

But it was in the area of internal policies that Andropov appeared to be seeking policies to revive the society from its lethargy by jettisoning unrealistic plans and exaggerated expectations.

Although his proposals were outlined in general terms--in fact he criticized the current party program for being overly detailed--they seem to suggest that Andropov was prepared to abandone some cherished Soviet ideological principles in an effort to get the economy moving.

One such principle is the uravnilovka, under which most Soviet citizens gets relatively equal wages irrespective of their job performance. The other is the unquestioned supremacy of the central planners and bureaucrats. Yet another is the notion that the system is functioning well and that the country is on its way to reaching communism.

The Soviet economy has been growing at declining rates during the past four years, plagued by low labor productivity, worker apathy, four consecutively poor harvests, alcoholism and absenteeism. Consumerism, cynicism and resignation have grown. The Kremlin's efforts to raise living standards have failed.

In view of what is perceived here as America's "permanent hostility," Andropov with his speech was trying to galvanize the party and country to get on the move again and to rely on its own resources. A change in the economic system that is not functioning properly is "inevitable" and there was no way of avoiding it, he said.

Before ending the session devoted to ideology, the Central Committee made several personnel changes. It named Vitaly Vorotnikov, 56, who previously served as a deputy premier of the Russian Federation and more recently as ambassador to Cuba, an alternate member of the Politburo.

Politburo member Grigori Romanov, 60, Communist chief of the Leningrad area for the past 13 years, was today appointed a secretary of the Central Committee. His move to Moscow and the combination of the two positions make Romanov one of the key figures in any future succession.

The plenum elected five new members to the Central Committee, including Marshal Sergei Akhromeev, the first deputy chief of Soviet general staff, and Gen. Vitali Shabanov, a deputy defense minister. The premier of the Russian Federation, alternate Politburo member Mikhail Solomentsev, was appointed head of the party's control commission. He succeeded Politburo member Arvid Pelshe, who died recently.

In a move that had been expected, the Central Committee expelled Gen. Nikolai Shcholokov, 72, who served for 16 years as minister of interior until being removed by Andropov in December. He and another powerful member of the Central Committee, Sergei Medunov, 68, also expelled today, have been investigated on corruption charges.

The struggle against corruption has been Andropov's favorite theme since he took power, and today he again warned that he intended to stamp out the misuse of office for personal gain.

In what is a major ideological departure in a society run on the basis of Marxist-Leninist ideology, Andropov said today that the Soviet society at the moment finds itself in the "beginning stage of advance socialism."

The party program adopted under Khrushchev says that the Soviet Union had already passed the "socialist stage" and that it was "building communism." Although Brezhnev had not attempted to change the program, he had attempted to bring the ideology closer to reality by asserting that the Soviet society was at the stage of "developed socialism" with communism remaining its ultimate goal.

A western reader may find such arcane distinctions insignificant, but they cut deep here. They indicate, above all, Andropov's political strength and his determination to tackle the basic dogma after only seven months in power. In theory, more than in practice, the party program is a blueprint for development of a centrally planned society.

In the course of his speech, Andropov placed his greatest emphasis on the need to increase labor productivity and improve organization of labor. Referring to the apathy of the farm population and the flight of young people to the cities, he said the state should create "civilized" conditions in the countryside.

The present economic mechanism, he said, was blocking technological progress. The system of planning now in force, he said, penalized innovative managers while rewarding those who stick to old-fashioned methods. He added that the time has come to change the entire system of bonuses and rewards in order to increase productivity.

"What is the use of a trade union organization that does not dare raise its voice in defense of the interests of the working people," he said in criticizing the frequent muzzling of the unions by party and industrial managers.

Soviet industries, he continued, are producing items of such shoddy quality that "nobody wants to buy them." He acknowleged that Soviet people are subjected to shortages of food and other goods and that the system is far from functioning well.

The "immediate" aim, he said, is "to bring to order what we have, to ensure the most reasonable utilization of the country's" productive resources and "the smooth and uninterrupted work" of the entire economy.

This is needed, Andropov said, to move to "intensive development." Speaking about the need to provide financial incentives, he asserted that people who work better should get higher wages.

"As to full equality in the sense of equal use of material boons, this will be possible only under communism," he added.

Speaking about the socialist community, Andropov for the first time acknowleged differences within COMECON, the Soviet Bloc economic common market, but said "the existing differences do not interfere with the development of cooperation."

Andropov called for a greater integration of Eastern European economies but made an extraordinary acknowledgement of cultural and historical differences among socialist states.

During the past two decades, he said, Moscow's relations with its Eastern European partners "have enriched our idea" of socialism and "shown more vividly how diverse and complex" the alliance is.