* Example for n with the units identical 

bind 
MTTF 1/(10*10^4)
MTTR 1/(1.25*10^8)
end

block ser(n) 
comp Unit ss_unavail(1/MTTF, 1/MTTR)
kofn sys 1,n,Unit
end

func U(n) sysprob(ser;n)
func A(n) 1-U(n)

* variable named downtime is the system downtime in minutes per year
func downtime(n) 60*8760*U(n)

* Mean Time To System Restoration
func MTTSR(n) MTTR/n

* Mean Time To System Failure
func MTTSF(n) A(n) * MTTSR(n) / U(n) 

* Mean Time To System Failure
func MTTSF1(n) ((1+(MTTF/MTTR))^n - 1)*MTTR/n  

* vary the value n 
loop n,2,5
  expr  A(n), U(n) ,downtime(n), MTTSF(n), MTTSF1(n), MTTSR(n)
end

end


