WHEN WE last looked in on the effort to remodel the Senate, the ambitious blueprint drawn up by Sen. Adlai Stevenson's special panel was about to be reviewed by the Rules Committee. The result has been what you might expect when architects' work is gone over by political engineers: A considerable amount of good design has been sacrificed to practical concerns. For instance, under pressure from affected groups, the Rules panel voted not to abolish the separate committees on small business and veterans. There was heavy resistance to consolidating the authority over transportation policy, so that idea was shelved - leaving railroads in the hands of one committee, highways in the custody of another, and mass transit to be managed by a third.

Some key parts of the original proposal have survived. Authority over energy policy is to be pulled together in one place. That is a notable advance. There is agreement on abolishing several panels whose day has passed, including the Joint Committee on Atomic Energy and the District of Columbia Committee, which became a superfluity with the advent of home rule (D.C. matters will henceforth be handled by a committee on government affairs.) The rules group also resisted appeals to perpetuate the separate committees on nutrition and on the aging. Those topics would be addressed, as they should be, in connection with related social welfare policies.

In what may be the most significant step of all, the reorganization plan would curb the sprawl of sub-committees - the vehicles most senators use to gain prestige, publicity and extra staff. Now a single senator may serve on 18 or 20 subcommittees and , if he is a Democrat, chair five or six of those. Under the pending plan he would be limited, in general, to serving on eight and heading three. In theory, this will enable him to manage his time more sensibly, become more expert in selected policy fields and serve his constituents more effectively. Meanwhile, the public will have a much better idea of who is really responsible for action or non-action in each field. The theory is impeccable. We'll see how long the self-discipline lasts.

Out overall conclusion is this: The Rules Committee has advanced a useful modernization plan. We urge the fullSenate to adopt it this week.