It used to be that when a junior professor was denied tenure, the department head had a ready-made excuse for the young scholar--"Sorry, we just don't have a `slot' available for you."

That excuse can't be used anymore. Because of a new system of allotting faculty appointments that has been quietly instituted in the past year, department heads no longer have that automatic justification for denying junior faculty lifetime positions.

This does not mean that Harvard's junior professors will automatically be elevated to tenured posts--even if their work seems to warrant the promotion. But the switch, administrators and professors say, may mark the beginning of a critical transition in the tradition-bound Faculty of Arts and Sciences (FAS).

In the old days there was the Graustein system--a complex formula dating from the 1940s used to determine the number of senior-level posts in each department. Everyone, it seemed, criticized it, and few fully understood it.

The Graustein system was built around a set of premises that most faculty now consider obsolete. Graustein, the Harvard mathematician who invented the formula, calculated faculty distribution based on the assumption that the faculty would not grow and that new academic fields would not arise.

But administrators say the system that has replaced it, which grants each department a certain number of Full Time Equivalents or FTEs, is designed to introduce flexibility and consistency into the faculty appointments process. Perhaps the most important change is that when junior faculty members come up for tenure, there does not have to be a senior-level vacancy for the scholars to be considered for lifetime posts.

As Associate Dean for Academic Planning Phyllis Keller describes it, the new system is "a comprehensive savings account and checkbook given to departments, where the currency is positions rather than money."

Under the new system, department heads, in conjunction with administrators and senior faculty, now have the power to make long-range plans for their department without going hat in hand to beg the dean for each new appointment that is made.

The new system, the project of Dean of the Faculty A. Michael Spence, would provide a department with an annual budget that is expected to cover the salaries of all junior and senior professors for the year. Each department is allocated a "steady-state" number of positions--computed by adding up the number of both junior and senior posts that departments had under the old system--that it is allowed to fill and is then given leeway to decide the exact balance between junior and senior faculty.

Although searches for tenured posts still require the dean's authorization, under the new system, personal power politics and individual negotiations with the dean of the Faculty have become less frequent because departments don't have to lobby for every professor they seek to hire.

"One thing about the Graustein is that not all faculty appreciate how much negotiation was going on between some powerful individuals and the dean," says Arnold Professor of Science William H. Bossert'59.

Eventually, administrators and some department heads hope that the shift will help produce fairer consideration of junior faculty members and an increase in the number of women and minorities on the faculty. That task, as administrators are quick to acknowledge, is far from a simple one--the tradition of the Graustein system will take a long time to die.

Faculty members on both sides of the political fence are suspicious of the new system. Many long-time Harvard professors fear the new way of computing faculty allotments will result in excessive growth in "faddish" areas, Bossert says. Some junior faculty, on the other hand, say the change is meaningless and assume that Harvard traditions are not so easily eradicated.

Most faculty interviewed say that while department heads are comfortable with the changes, other professors don't yet understand how the new system works. And many add that they are hesitant about its implications.

"The faculty as a whole are still in the process of understanding everything about it," says Associate Dean for Undergraduate Education David R. Pilbeam. Pilbeam estimates that it will be at least five years before the system's effects can be assessed.