Georgetown-based Syscon Corp., in a move to tighten its organizational structure, has promoted its two top executives one notch and given them more clearly defined responsibilities.

In an announcement last week, Jose J. Yglesias, 54, formerly president, was named chairman and chief executive officer of the growing software company. Edwin E. Tritch, 56, formerly executive vice president, was appointed president and chief operating officer. Both are directors and founders of the 18-year-old company.

The announcement came a few days before Syscon reported that it had reached the $100 million sales mark in fiscal 1984. Revenue for the year ending Nov. 30, 1984, rose 20 percent over the previous year to $104 million from $87 million, while profits for the same period climbed 16 percent to $4.1 million ($1.31 a share) from $3.5 million ($1.22).

For the company's fourth quarter, earnings were $1.888 million (38 cents), up from $1.102 million (35 cents) a year before.

Syscon, which employs 600 people in the Washington area, develops computer software systems for the Department of Defense and other branches of the federal government.

"After 18 years of uninterrupted growth," Yglesias said, "we are now a $100 million company. . . . These management changes essentially reflect a division of responsibilities at our company which is necessary as we plan for our continued growth and expansion in the marketplace."

Yglesias, who had shared responsibility for daily operations with Tritch, will devote his time to the company's long-range planning, research and development and investor relations.

As president, Tritch will manage daily operations of the firm. He will have direct responsibility for its three major geographical divisions, each of which account for between $30 million and $40 million in sales.

Finally, Syscon Corp. has named three new vice presidents: Robert S. Kidwell, vice president in charge of advanced computer projects; Christine Reynolds, vice president and general manager of the San Diego division; and Dennis Vaughan, vice president in charge of special projects.