MATLAB Simulation of Production Machines Failure - MTBF & MTTR

Question

I want to model production machines' failure in terms of MTBF(mean time between failure) and MTTR(mean time to repair), with exponential distribution.

Actually i am modelling a Discrete Event Simulatin (DEV/DEVS) problem. The problem is concerned with FMS(flexible manufacturing system). It involves six unreliable (likely to fail) machines which can fail during operation.

1. I want to know how to model unreliable machines in terms of MTBF & MTTR using exponential distribution.
2. Also, I want to study the effect of varying MTBF and MTTR values on the problem. e.g. Distribution used: Exponential;MTBF:400,600.....;MTTR:25,50...

Answer 1

Check this and the related folders, for examples of Stochastic Processes simulated under matlab, in particular, an example of a Poisson Process:

% poisson.m simulates a homogeneous Poisson process
lambda=10;      % arrival rate
Tmax=3;         % maximum time
T(1)=random('Exponential',1/lambda);
i=1;
while T(i) < Tmax,
    T(i+1)=T(i)+random('Exponential',1/lambda);
    i=i+1;
end
Y=zeros(1,i-1);
plot(T(1:(i-1)),Y,'.');

Just remember that, the Poisson Process is a chain of exponential events, as the very code suggests, Thus, for representing your machine, you just need to adapt the above code adding as many variables as machines you have...........

The rest, is part of your homework......