## MAPLE  May 1, 2004. 

mm1 := proc( lam, mu )
       local k, P0, Lq, L, Wq, n,p7;
 
       k:=1:
       P0 := evalf(1-lam/mu); 
       printf(` Probability that no units are in the system:  %5.4f\n\n`,P0);
       Lq := evalf( lam^2/mu/(mu-lam) );
       printf(` Average number of units waiting for service: %3.2f\n\n`,Lq);
       L := Lq + lam/mu;
       printf(` Average number of units in the system:       %3.2f\n\n`,L);
       Wq := Lq/lam;
       printf(` Average time a unit spends in the queue:     %3.2f\n\n`,Wq);
       W := Wq + 1/mu;
       printf(` Average time a unit spends in the system:    %3.2f\n\n`,W);
       Pw := evalf(lam/mu); 
       printf(` Probability an arriving unit must wait:      %5.4f\n\n`,Pw);
       printf(` Prob. n units in the system:\n n:   0     1     2     3    `);
       printf(` 4     5     6     >=7\nPn: %3.3f`,P0);
       p7 := 1-P0;
       for n to 6 do 
        P0 := P0*lam/mu;  p7 := p7-P0; printf(`  %3.3f`,P0);
       od;
       printf(`  %3.3f\n`,p7);
end;