Probability of more than n machines down any hour?












4












$begingroup$


Suppose we have $N$ identical machines, at any given hour, there's a chance $P$ that any given machine went down. A down machine takes $T$ hours to recover. How do I calculate the chances that in a given longer interval $Y$ (assume $Y >> T$), what are the probability that there exists hour $t$, $0 < t < Y$, such that at $t$ there are more than $R$ machines that are down?










share|cite|improve this question











$endgroup$








  • 2




    $begingroup$
    A Poisson distribution describes this situation.
    $endgroup$
    – David G. Stork
    Jan 4 at 4:19






  • 1




    $begingroup$
    Do you want to know the probability more than $R$ machines are down at time $Y$ or the probability that there exists time $0<t<Y$ such that more than $R$ machines are down at time $t$?
    $endgroup$
    – SmileyCraft
    Jan 4 at 4:21










  • $begingroup$
    @SmileyCraft, the later, the probability that there exists time 0 < t < Y such that more than R machines are down at time t.
    $endgroup$
    – Vance
    Jan 4 at 4:27










  • $begingroup$
    @DavidG.Stork, how would I apply Poisson distribution to this scenario? I can maybe find the average number of machines going down per year based on the P, and calculate the chances for r < R, but that does not necessarily answer if they are concurrent?
    $endgroup$
    – Vance
    Jan 4 at 4:36










  • $begingroup$
    This is a Poisson distribution with expected number of faults in a given hour of $P N$. That determines all probabilities.
    $endgroup$
    – David G. Stork
    Jan 4 at 6:38
















4












$begingroup$


Suppose we have $N$ identical machines, at any given hour, there's a chance $P$ that any given machine went down. A down machine takes $T$ hours to recover. How do I calculate the chances that in a given longer interval $Y$ (assume $Y >> T$), what are the probability that there exists hour $t$, $0 < t < Y$, such that at $t$ there are more than $R$ machines that are down?










share|cite|improve this question











$endgroup$








  • 2




    $begingroup$
    A Poisson distribution describes this situation.
    $endgroup$
    – David G. Stork
    Jan 4 at 4:19






  • 1




    $begingroup$
    Do you want to know the probability more than $R$ machines are down at time $Y$ or the probability that there exists time $0<t<Y$ such that more than $R$ machines are down at time $t$?
    $endgroup$
    – SmileyCraft
    Jan 4 at 4:21










  • $begingroup$
    @SmileyCraft, the later, the probability that there exists time 0 < t < Y such that more than R machines are down at time t.
    $endgroup$
    – Vance
    Jan 4 at 4:27










  • $begingroup$
    @DavidG.Stork, how would I apply Poisson distribution to this scenario? I can maybe find the average number of machines going down per year based on the P, and calculate the chances for r < R, but that does not necessarily answer if they are concurrent?
    $endgroup$
    – Vance
    Jan 4 at 4:36










  • $begingroup$
    This is a Poisson distribution with expected number of faults in a given hour of $P N$. That determines all probabilities.
    $endgroup$
    – David G. Stork
    Jan 4 at 6:38














4












4








4


2



$begingroup$


Suppose we have $N$ identical machines, at any given hour, there's a chance $P$ that any given machine went down. A down machine takes $T$ hours to recover. How do I calculate the chances that in a given longer interval $Y$ (assume $Y >> T$), what are the probability that there exists hour $t$, $0 < t < Y$, such that at $t$ there are more than $R$ machines that are down?










share|cite|improve this question











$endgroup$




Suppose we have $N$ identical machines, at any given hour, there's a chance $P$ that any given machine went down. A down machine takes $T$ hours to recover. How do I calculate the chances that in a given longer interval $Y$ (assume $Y >> T$), what are the probability that there exists hour $t$, $0 < t < Y$, such that at $t$ there are more than $R$ machines that are down?







probability probability-distributions






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Jan 4 at 15:55







Vance

















asked Jan 4 at 4:17









VanceVance

212




212








  • 2




    $begingroup$
    A Poisson distribution describes this situation.
    $endgroup$
    – David G. Stork
    Jan 4 at 4:19






  • 1




    $begingroup$
    Do you want to know the probability more than $R$ machines are down at time $Y$ or the probability that there exists time $0<t<Y$ such that more than $R$ machines are down at time $t$?
    $endgroup$
    – SmileyCraft
    Jan 4 at 4:21










  • $begingroup$
    @SmileyCraft, the later, the probability that there exists time 0 < t < Y such that more than R machines are down at time t.
    $endgroup$
    – Vance
    Jan 4 at 4:27










  • $begingroup$
    @DavidG.Stork, how would I apply Poisson distribution to this scenario? I can maybe find the average number of machines going down per year based on the P, and calculate the chances for r < R, but that does not necessarily answer if they are concurrent?
    $endgroup$
    – Vance
    Jan 4 at 4:36










  • $begingroup$
    This is a Poisson distribution with expected number of faults in a given hour of $P N$. That determines all probabilities.
    $endgroup$
    – David G. Stork
    Jan 4 at 6:38














  • 2




    $begingroup$
    A Poisson distribution describes this situation.
    $endgroup$
    – David G. Stork
    Jan 4 at 4:19






  • 1




    $begingroup$
    Do you want to know the probability more than $R$ machines are down at time $Y$ or the probability that there exists time $0<t<Y$ such that more than $R$ machines are down at time $t$?
    $endgroup$
    – SmileyCraft
    Jan 4 at 4:21










  • $begingroup$
    @SmileyCraft, the later, the probability that there exists time 0 < t < Y such that more than R machines are down at time t.
    $endgroup$
    – Vance
    Jan 4 at 4:27










  • $begingroup$
    @DavidG.Stork, how would I apply Poisson distribution to this scenario? I can maybe find the average number of machines going down per year based on the P, and calculate the chances for r < R, but that does not necessarily answer if they are concurrent?
    $endgroup$
    – Vance
    Jan 4 at 4:36










  • $begingroup$
    This is a Poisson distribution with expected number of faults in a given hour of $P N$. That determines all probabilities.
    $endgroup$
    – David G. Stork
    Jan 4 at 6:38








2




2




$begingroup$
A Poisson distribution describes this situation.
$endgroup$
– David G. Stork
Jan 4 at 4:19




$begingroup$
A Poisson distribution describes this situation.
$endgroup$
– David G. Stork
Jan 4 at 4:19




1




1




$begingroup$
Do you want to know the probability more than $R$ machines are down at time $Y$ or the probability that there exists time $0<t<Y$ such that more than $R$ machines are down at time $t$?
$endgroup$
– SmileyCraft
Jan 4 at 4:21




$begingroup$
Do you want to know the probability more than $R$ machines are down at time $Y$ or the probability that there exists time $0<t<Y$ such that more than $R$ machines are down at time $t$?
$endgroup$
– SmileyCraft
Jan 4 at 4:21












$begingroup$
@SmileyCraft, the later, the probability that there exists time 0 < t < Y such that more than R machines are down at time t.
$endgroup$
– Vance
Jan 4 at 4:27




$begingroup$
@SmileyCraft, the later, the probability that there exists time 0 < t < Y such that more than R machines are down at time t.
$endgroup$
– Vance
Jan 4 at 4:27












$begingroup$
@DavidG.Stork, how would I apply Poisson distribution to this scenario? I can maybe find the average number of machines going down per year based on the P, and calculate the chances for r < R, but that does not necessarily answer if they are concurrent?
$endgroup$
– Vance
Jan 4 at 4:36




$begingroup$
@DavidG.Stork, how would I apply Poisson distribution to this scenario? I can maybe find the average number of machines going down per year based on the P, and calculate the chances for r < R, but that does not necessarily answer if they are concurrent?
$endgroup$
– Vance
Jan 4 at 4:36












$begingroup$
This is a Poisson distribution with expected number of faults in a given hour of $P N$. That determines all probabilities.
$endgroup$
– David G. Stork
Jan 4 at 6:38




$begingroup$
This is a Poisson distribution with expected number of faults in a given hour of $P N$. That determines all probabilities.
$endgroup$
– David G. Stork
Jan 4 at 6:38










0






active

oldest

votes











Your Answer





StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
});
});
}, "mathjax-editing");

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "69"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});














draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3061320%2fprobability-of-more-than-n-machines-down-any-hour%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown

























0






active

oldest

votes








0






active

oldest

votes









active

oldest

votes






active

oldest

votes
















draft saved

draft discarded




















































Thanks for contributing an answer to Mathematics Stack Exchange!


  • Please be sure to answer the question. Provide details and share your research!

But avoid



  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.


Use MathJax to format equations. MathJax reference.


To learn more, see our tips on writing great answers.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3061320%2fprobability-of-more-than-n-machines-down-any-hour%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown





















































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown

































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown







Popular posts from this blog

Bressuire

Cabo Verde

Gyllenstierna