Criticism of Pentagon management and of weapons cost overruns is as perennial here as summer humidity. But lately, interest in making the Defense Department more efficient and effective has been unprecedented. For example: a string of recent government reports critical of weapons procurement; high-level recommendations from private business executives on how to save money; suggestions that weapons are not adequately tested before bought; announcements by members of Congress - including notable hawks - that they intend to look for cost causes and possible reforms.
The latest salvo in this spate of activity comes from within the Pentagon itself. An internal audit finds that the Air Force and Navy have been paying prices for aircraft spare parts that have doubled and tripled in just a few years. The armed services and defense contractors are sharply criticized in this finding of the Defense Department's inspector general.
Meeting with Pentagon reporters, Deputy Secretary of Defense Paul W. Thayer Tuesday promised ''fast and immediate'' corrective action.
''I can assure you that this is not going to be treated lightly,'' said Mr. Thayer, former chairman and chief executive of LTV, a major builder of military aircraft. ''We will take whatever action is necessary to stop it and whatever penalties will be necessary to impress upon people that this is not right. . . . If it has to be severe, it will, and it may involve people finding new employment.''
The Reagan administration came into office promising to banish waste, fraud, and abuse from federal government, including the Pentagon - the one agency it intended to beef up substantially. It can point to some gains in this area.
But in the 21/2 years it has been in office, the administration also has learned how difficult it is to change established patterns, especially when they involve entrenched and entangling alliances within the so-called iron triangle: Congress, the military services, and weapons suppliers.
And now it faces a special crunch as the prospect of continued enormous federal deficits and a growing public disenchantment with the intended rearming of America - both of which are reflected in Congress - come up against this week's debate on Capitol Hill over the 1984 Pentagon budget. In the Defense Department itself, these same difficulties are on the minds of Thayer and others who sit on the Defense Resources Board and who, over the next three weeks, will be giving initial shape to the fiscal 1985 defense budget.