Richard P. Godwin, the corporate executive hired by Defense Secretary Caspar W. Weinberger to improve the way the Pentagon develops and produces new weapons, plans to resign Tuesday because he feels his attempts at reform failed to gain the Pentagon's backing, senior Defense Department officials said yesterday.

Godwin, in an interview with The Washington Post, said his chief problem is that "I can't make anything stick." Breaking a long public silence to respond to criticism from other senior Pentagon officials about his performance in the job, Godwin added that "the thing I can't accept is to be ignored by the system."

Godwin was appointed a year ago to the new post of undersecretary of defense for acquisition, expecting to become one of the most powerful officials in the Pentagon with wide-ranging authority for weapons purchases. His appointment came after several scandals caused a panel of experts appointed by President Reagan to issue a generally scathing assessment of how such purchases are conducted.

But several officials said that Godwin's ideas -- which he said were drawn from the panel's recommendations -- generated intense resistance within the Pentagon and had only modest impact on the unwieldy, $170 billion weapons purchasing system. Godwin's brusque corporate style, colored by a desire to win every battle, never won much support from the military service secretaries who dominate weapons purchasing, several officials said.

But other officials, including Air Force Secretary Edward C. Aldridge Jr., said the Pentagon has made vigorous efforts to implement reforms and effectively prevent new "horror stories."

Godwin, who previously was president of the Bechtel Group Inc., an international engineering and construction company, said his goal was "to simplify, to improve cost effectiveness and have a more efficient acquisitions system by using commercial business practices as contrasted to military ones or bureaucratic ones."

"When we brought in a new system and superimposed it on top of the current one," Godwin said, "we came down on everyone's toes."

Some congressional sources and Pentagon allies of Godwin said his resignation will complicate the Pentagon's efforts to implement recommendations of the Commission on Defense Management chaired by former deputy defense secretary David Packard, because any replacement would have little more than a year to complete the job during the current administration.

Robert B. Sims, the Pentagon's assistant secretary of defense for public affairs, yesterday disputed allegations that the department had been foot-dragging on Packard's recommendations. "All of the substantive Packard commission recommendations have been supported by the department," Sims said.

Sims also said Weinberger and deputy secretary of defense William Howard Taft IV "are supportive of the Packard commission recommendations and have supported Mr. Godwin in the setting up of the acquisition office."

But several officials said Godwin was especially unhappy about Taft's rejection -- with Weinberger's concurrence -- of a proposal that senior Army, Navy and Air Force officials responsible for arms purchases report directly to Godwin's office, effectively ending a longstanding arrangement in which the managers report to the secretaries of those military services.

Aldridge recently told Pentagon reporters that the proposal was fiercely resisted by all three military service secretaries on the grounds that "it would separate those people that have acquisition responsibility from those people who have the responsibility of operating the forces" once they are fully developed and deployed.

"It's like the White House directing an assistant secretary of defense without telling Weinberger," Aldridge said. "That wouldn't fly more than about two seconds."

Godwin replied that his aim was not to control individual weapons programs but to make certain that he would obtain accurate and timely warning of potential troubles. Twelve to 15 layers of bureaucracy lie between his office and program managers, Godwin said, while the Packard commission favored maintaining only three layers.

"When problems occur and you've got these layers of bureaucracy, the information gets so levelized, normalized and truncated, you can't even recognize it," Godwin said. "The service commands can protect the service secretaries from learning about it, and they can protect us. Meanwhile, you're in the soup, and you don't even know about it until 10 to 15 months later."

"You couldn't possibly do this in industry," Godwin said. "You'd be broke by next week."

Aldridge said he and other service secretaries also objected to Godwin's plan to install a computer network for analyzing expenditures on major weapons programs. "Dick Godwin wants a computer on the back of his desk that gets all of the information from the B1 program office or the F15 program office on day-to-day execution of the programs," Aldridge said.

"He's going to pick up the phone and say, 'Hey, what's happening on the F15? I want you to move X dollars from this to that.' That's the kind of thing we're objecting to," Aldridge said.

Godwin responded, however, that "it's about time someone had such a computer on his desk at the Pentagon. No business could run without it." He added that "we can't have a decision based simply on how glib a service secretary is or how good his slide presentation is . . . . We are supposed to be working on a defense of the United States, not a defense of the U.S. Air Force."

Yet another dispute between Godwin and other senior officials concerned his desire to limit membership in the senior policymaking committee for arms research and development to a few officials who reported directly to him, plus the Defense Department comptroller.

Several high officials, such as Pentagon policy undersecretary Fred C. Ikle, would have been excluded from the committee, called the Defense Acquisition Board, under a Godwin recommendation that Weinberger and Taft recently overturned.