Method for simulating a system having multiple failure modes
View Patent ↗A method is described for determining the effectiveness of maintenance or other improvements to a system having multiple sections and multiple modes of failure. The method uses a simulation model that is dynamic in that it can change during a simulation run to show how a system event such as a failure of one system section can effect a different system section. By running the simulation model multiple times, it may become apparent which system section will benefit most from maintenance or other improvements.
1. A method for simulating a system comprised of sections and having multiple failure modes, the method comprising the following steps:
a) in a computer, obtaining system event data for each of the sections, the system event data comprising the timing of system events, and creating predetermined covariates based on the system event data;
b) statistically modeling a lifetime of each of the sections as a function of system event data;
c) simulating the system based on a dynamic simulation model, and recalculating the lifetime of at least one of the sections between at least one type of system event; and
d) implementing changes to the dynamic simulation model during the step of simulating the system.
2. The method of claim 1 further comprising a step of estimating system event data.
3. The method of claim 1 wherein the steps are accomplished in the following order: a, b, c, and d.
4. The method of claim 3 wherein the system is selected from a group consisting of a continuous manufacturing system and a non-continuous manufacturing system.
5. The method of claim 3 further comprising the step of e) prioritizing an improvement plan for the system.
6. The method of claim 5 wherein the step of prioritizing an improvement plan is performed in real time.
7. The method of claim 1 further comprising the step of prioritizing an improvement plan for the system in an effort to minimize system events.
8. A method for simulating a discrete product manufacturing system comprising sections and having multiple failure modes the method comprising the following steps:
a) in a computer, defining the system;
b) identifying system sections that can cause system events;
c) identifying system events that can affect the reliability of the system;
d) statistically modeling a lifetime of the system;
e) building a simulation model which takes into account interactions between sections as system events occur during a simulation run;
f) conducting a simulation run; and
g) calculating the lifetime of the system between at least one the of system event; and
h) implementing system improvement projects as a result of evaluating the effect of system changes or system event changes on the lifetime of the system.
9. The method of claim 8 further comprising the step of forecasting a future system performance by conducting multiple simulation runs.
10. The method of claim 9 wherein the step of forecasting a future system performance is performed in real time.
11. The method of claim 8 further comprising the step of evaluating the effect of system section or sub-section changes on the lifetime of the system.
12. The method of claim 8 wherein the step of building a simulation model which takes into account interactions between sections as system events occur during a simulation run further comprises:
initializing system variables and events;
calculating an initial lifetime of each system section;
calculating a system lifetime;
calculating a lifetime used up for each system section;
calculating an additional lifetime for each system section based on current system events;
calculating a new lifetime for each system section; and
calculating a new system lifetime.
13. A method for simulating a system having multiple failure modes comprised of sections and sub-sections, the method comprising the following steps:
a) in a computer, defining the system;
b) identifying system sections that can cause system events;
c) identifying system events that can affect the reliability of the system;
d) statistically modeling a lifetime of the system;
e) building a dynamic simulation model which takes into account interactions between sections as system events occur during a simulation run;
f) conducting multiple simulation runs by either changing the reliability of at least one system section, or by changing the impact of a system event on at least one machine section during each simulation run; and
g) implementing system improvement projects as a result of evaluating the effect of system section changes or system event changes.
14. The method of claim 13 further comprising the steps of:
calculating an initial lifetime of each system section; and
calculating a system lifetime.
15. The method of claim 14 further comprising the steps of:
calculating a lifetime used up for each system section; and
calculating an additional lifetime for each system section based on current system events.
16. The method of claim 15 further comprising the steps of:
calculating a new lifetime for each section; and
calculating a new system lifetime.
17. The method of claim 16 wherein the system comprises a manufacturing system.
18. The method of claim 17 wherein the manufacturing system is adapted to produce disposable absorbent products.