If salary security, love of coworkers and daily peace of mind are important to you, then the only thing worse than NOT being a manager or supervisor in the giant federal establishment is being a supervisor or manager.

Starting later this year, every manager or supervisor in government at Grade 13, 14 and 15 is going to be put aboard an intentionally tough performance treadmill. It promises a shot at the brass ring worth extra dollars for the best, and half-a-loaf pay raises for others.

When the dust clears from the pending shakeup of management resources, an estimated 38,000 new mid-level workers -- including thousands in this town -- are going to discover that overnight they have been designated as managers or supervisors. It will be a new performance and pay ball game for all of them.

Under the civil service reform act, federal agencies must -- no later than October 1981 -- set up a separate performance pay system for their supervisor people. Most agencies already are in the process of doing it. Many expect to have it running for some workers by this fall.

The performance pay system is designated to make managers and supervisors work harder, and get better results from their employes. It has incentives and disincentives.

To begin with, managers and supervisors in Grades 13 through 15 (pay range $27,453 to $47,500) will not get the full amount of regular October adjustments that other federal workers who are not managers or supervisors automatically will get. This October that raise is due to be 5.5 percent.

Supervisors and managers are guaranteed only half of the October pay adjustment. For more than that, they must get top marks from their bosses. Those bosses who do not measure up would get 2.7 percent or thereabouts, while the employes working under them and their nonmanagement colleagues get the full 5.5 percent.

Bosses who do outstanding work can be given the full amount of the October raise, or more, up to a maximum representing the top 10th step of their particular pay grade.

One of the big things to be decided is just who is a manager or supervisor? Currently the government has 72,000 at that level out of a total GS 13 through 15 work force of 188,000.

In the Washington metro area there now are 30,000 employes at Grade 13; 23,000 at Grade 14 and 15,700 at Grade 15. Nobody knows for sure how many here currently are designated as managers or supervisors. But many who are not now will be.

New definitions of "supervisor" in the law make it possible that an individual who supervises or gives work to one other individual, for example a secretary, can be considered a supervisor. Managers will be people designated by agencies whose actions have an impact or effect on agency policies. That could take in a lot more people. Insiders say the manager supervisor population of 72,000 easily could jump to 110,000 -- or more -- when the new guidelines are in place.

So for many managers and supervisors, and for many about-to-bedesignated as managers and supervisors, the upcoming October pay raise is the last one they will share on an equal basis with their nonmanagement coworkers.

Some supervisors and managers are thrilled at the prospect of being part of a performance pay system. If run well, they see it as a chance to get extra rewards (including one-shot cash bonuses)for being better than average. And they see it as a chance for their not so hot-shot peers to get what they deserve, which is half of what everybody else gets.

Other supervisors and managers are not so thrilled about the new pay system. They think it will set managers against managers (since pay will come out of a single merit pay pot), and find it unfair that they must take the financial risks for the often thankless job of managing -- and sometimes firing -- people that their nonmanagement colleagues do not have to do.