Computed Column Bit based on other Bit Columns
Do you mean IsOk = 1 if the other three bit columns all = 1 else IsOk = 0?

If so: -

CREATE TABLE #Employee
(
[empNumb]       [INT] identity(1,1) PRIMARY KEY,
[IsOk]          AS [HasValidHours] &amp; [NoDemerits] &amp; [NoAccidents],
[HasValidHours] [BIT] NOT NULL,
[NoDemerits]    [BIT] NOT NULL,
[NoAccidents]   [BIT] NOT NULL
);


See &amp; (Bitwise AND) (Transact-SQL)