How to Read Excel Solver's Sensitivity Report

[@airhunter619]

Bought you a coffee. you are a better teacher than my professor who paid way to much.

[@TallysYunes]

Thank you very much for your support, Collin!

[@w1nterB]

slow and steady, explained every corner of the topic.Thnak You!

[@JackRyan101]

Really really helpful. I was totally confused by the way it was taught in class. Thank you.

[@TallysYunes]

You're welcome! Glad to hear that the video helped!

[@yuanzhang8843]

Thank you so much, Dr. Tallys for uploading this video which is really helpful for me to understand the sensitivity report!

[@ladobot8157]

Sir, you are a hidden gem in the KZbin.

[@TallysYunes]

Haha! You are too kind! Thank you!

[@sougat18]

The best conceptual lecture I have found on this topic. Thank you so much

[@TallysYunes]

Thank you! You're very welcome!

[@jend892]

This is incredibly helpful, thank you for the concise explanations!

[@TallysYunes]

You're welcome! Glad to hear it was useful!

[@matlholelosaba4977]

Recorded four years ago and still relevant and so helpful. I wonder how this will change with new developments in Excel and the use of AI.

[@giggle_box16]

I undoubtably enjoyed your video. I subscribed right away.

[@TallysYunes]

Awesome! Thank you!

[@Ahmedbahgat-u1s]

such a great man, you saved our life

[@TallysYunes]

You're welcome.

[@jaiso434]

definitely the best explanation i have found.

[@TallysYunes]

Thank you! I'm happy to hear the video has been helpful.

[@jinlee1874]

this is the best explanation!! thank you very much!!!

[@TallysYunes]

Thank you! Glad it was helpful!

[@zacneil3712]

Thank you very much for your video!!! I have just one question why do we get get a positive number if we decrease the number of land by more than 5?

[@TallysYunes]

Because they are only using 40 acres, there's a surplus of 5 acres. This means that losing up to 5 acres won't affect what's happening now (shadow price of zero). However, if you were to lose more than 5 acres, the current solution would not be feasible anymore and they'd need to produce less, which would result in a smaller profit. Therefore, if the land available goes down below 40, that constraint will have a positive shadow price to indicate that "having more of this resource would increase the objective function (i.e. the profit)."

[@satwindersingh1797]

Wow, I loved it 10 classes summary in 35.52 Minutes

[@TallysYunes]

Haha! Glad you liked it! There's indeed a lot of information in this video.

[@sahilkhan2470]

This is really impresive done. Thank you for this

[@TallysYunes]

Glad you liked it!

[@jiawen6829]

This helps me a lot, thank you!

[@TallysYunes]

Glad it helped!

[@she8334]

this really helped, i had many questions and you literally have answered every single one of them in the video i will come here to update if i get full mark at my midterm...

[@TallysYunes]

So glad it helped! Good luck on the exam!

[@Thad1us23]

this video is by far the best explanation I've seen! Thank you! I have two questions, what steps would you take if you generated a sensitivity report and wanted to remove a constraint? 2nd, if you're adding a new variable (a new decision) but aren't given the profit (you are just given the constraints) how would you figure out the price of that unit?

[@TallysYunes]

If the constraint you are removing isn't binding/tight (i.e if the left hand side doesn't match the right hand side), and you are removing only that constraint, then the solution will remain the same. If the constraint is binding, then the sensitivity report does not tell you what will happen if you remove it completely, only what will happen to the value of the objective if you loosen or tighten the constraint (by changing the right-hand side). If you are adding a variable, to tell whether or not it will help the objective get better you compute the reduced cost as I explain. If the profit coefficient of that variable is unknown, you still do the same calculation but treat that profit coefficient as a variable p in the calculation and solve for it. As in, you can deduce what it would have to be for the reduced cost to be positive (assuming you are maximizing profit): p - (stuff in the parentheses) > 0, so p > (stuff in the parentheses), where "stuff in the parentheses" is what goes inside the parentheses of a reduced cost calculation as I explained in this particular video.

[@lydiekrickel6093]

Very well explained to be able to interpret these tables !

[@TallysYunes]

Thank you! I'm happy to hear it helped!

[@lindami3666]

Hello sir, I love your course which is very helpful!! Thank you!😀

[@TallysYunes]

Glad to hear that! Thank you!

[@outrage7063]

Thank you so much sir, I saw yours video one night before the exam.. And my exam went well... Thank you

[@TallysYunes]

You're welcome!

[@shubhamkumarsingh21]

best explanation of the sensi report.

[@TallysYunes]

Thank you!

[@abubakorsiddikrabby1769]

Thank you very much. nicely presented, sir

[@TRussell932]

Thanks for your video it really helped. How do you determine if your sensitivity report is reliable without making any changes within the allowable range?

[@TallysYunes]

Happy to hear it helped. I don't quite understand your question. How to determine it's reliable without making changes within the range? Do you mean you want to make changes outside the ranges? If that's the case, you can't use the report. You need to make these changes in the Excel model and re-solve the model.

[@TRussell932]

@@TallysYunes I'm doing a question where a sensitivity report was generated and it asked how do you determine if the sensitivity report is reliable.

[@TallysYunes]

I'd need more context. Is this homework? Maybe your teacher defined what they mean by "reliable" in class. One thing you can do is check to see if the report is consistent with the answer. For example: look at the final solution, is it really feasible? Plug the answer into the constraint formulas. Are the constraints that have zero slack matching the ones the report indicates? Is the shadow price equal to zero when the slack (difference between left-hand side and right-hand side values of a constraint) is not zero? etc. You can also look at the signs of the shadow prices: are they in the right direction? For example: does it make sense for a certain shadow price to have positive or negative sign? Think of the constraint in question. If it's a limited resource, getting more of it should improve your objective (where improve means increase for maximization and decrease for minimization). Is this happening? Etc.

[@TRussell932]

@@TallysYunes it's an assignment. I did replay the class video but that was never said however I like the way you are looking at it. I'll use this approach I think it should help. Many thanks!

[@AjayKumarRamachandran]

Amazingly explained..thanks for the video

[@TallysYunes]

Thanks! And you're welcome!

[@luci1474]

So well explained. Thank you so much. I needed help finding the ranges though.

[@TallysYunes]

You're welcome!

[@oksanamosenko1495]

Thank you, very helpful and well taught!

[@sweetdreams9826]

This is very helpful thank you!!! May i just ask how do we compute for the value of allowable increase and decrease?

[@TallysYunes]

The allowable increase and decrease are computed automatically by the Solver. We don't have to compute it ourselves. There is a calculation that can be done by hand, which is explained in any standard Linear Programming textbook.

[@sweetdreams9826]

@@TallysYunes , truly appreciate your response. Thank you!

[@kif2770]

Great explanation. Thank you!

[@TallysYunes]

You're welcome!

[@muniraakhmedova4551]

Phenomenally explained

[@TallysYunes]

Thank you!

[@MSMIMIBOOZ]

Thank u. This video saved my life.

[@TallysYunes]

You’re welcome. Happy to hear it was helpful.

[@ConfessionsofPrakharMittal]

Awesome video this clarified doubts even i missed it in class :)

[@TallysYunes]

Thanks! Glad it was helpful!

[@srijansaswat1620]

Thank you 😊 you literally saved me

[@TallysYunes]

You're welcome!! Glad the video was helpful!

[@matinajazmine]

Can you tell me where you got this questions? I want to use them for revision purposes😊

[@TallysYunes]

The questions are from my lecture notes. I have two more examples of sensitivity analysis if you want to practice further: kzbin.info/www/bejne/i6Hbd3mhh6-jjas and kzbin.info/www/bejne/pXXYYmt7iLaab6c

[@matinajazmine]

@@TallysYunes thank you so much

[@marmarmarmar7522]

It's very useful! Thank you!

[@COOLDUDE090]

So reduced cost of zero in wheat and corn means there is no impact if we remove wheat or corn? Like you said in alfafa example of $5 or -$5?

[@TallysYunes]

No. For variables that are not touching their lower or upper limits (in this case wheat and corn only have a lower limit of zero and neither or them is equal to zero) the reduced cost will always be set to zero by the solver and that zero doesn't really mean anything special.

[@ZoomSEdit]

Sir when I look the my constraints' of Excel sensivity analysis table, I see the whole RHS numbers equal to 0. But actually all of them have a number. Even in some constraints the LHS and RHS equals to each other. I need to write down the binding and nonbinding constraints but in this case it wouldn't be possible. All my 17 constraints' RHS's equal to 0. Why? How can I change this? Thank you

[@TallysYunes]

If you set everything up correctly, the values in the "RHS" column of the constraints table of the sensitivity report should match the right-hand side values of your constraints in the spreadsheet (assuming those were constants, rather than formulas). To check whether or not a constraint is binding, you just need to see if the value in the "Final Value" column of the constraint matches the value in its "RHS" column.

[@romeokodi9868]

You are great man thanks a lot

[@TallysYunes]

Thank you! And you're welcome. I'm happy to hear the video was helpful.

[@swaritagarwal6387]

Amazing! Really helpful

[@TallysYunes]

Thank you!

[@srabikumar]

Thank you! Great help.

[@TallysYunes]

You're welcome!

[@giwrgosgiwrgos958]

how can we figure out if there are other optimal solutions from the sensitivity report?

[@TallysYunes]

In the absence of a condition called "degeneracy," if the allowable increase or allowable decrease of the objective function coefficient of one or more variables equals zero, that indicates alternative optimal solutions exist. CAUTION: If the allowable increase or decrease for the right-hand side number of any constraint is zero, then the linear program is degenerate and the rule above (to detect alternative optimal solutions) doesn't work anymore.

[@giwrgosgiwrgos958]

@@TallysYunes thanks for that fast response I am getting my master and I work on Linear programms so I will need your help again xD

[@ZoomSEdit]

Thank you so much

[@TallysYunes]

You're welcome!

[@mssanaenglish739]

very well explained, hope my professor did the same :( now I know what this whole thing is about :))))))))))

[@TallysYunes]

Thank you! I'm happy to hear the video was helpful.

[@KURASREEJA]

Good video, Thank you!

[@rozerantasdelen7376]

great explanation thx

[@TallysYunes]

You're welcome!

[@DrFelemban]

Amazing video ... thank you for the video

[@TallysYunes]

You're welcome! Glad you liked it!

[@pushandeb187]

extremely useful

[@TallysYunes]

Thank you! Glad it was helpful!

[@abeyuassefa8279]

woooow! Thanks.

[@TallysYunes]

You're welcome!

[@lightningwaitforitakash]

Hit like if you are watching from GLIM for tomorrow's exam..!! 🤣😝

[@arghamukherjee7258]

lol..true

[@TallysYunes]

I hope the video is helpful and good luck to all GLIM students on tomorrow's exam!

[@chiaernlim3354]

What the meaning of final value ?

[@TallysYunes]

There's a final value column for the variable table (top table) and for the constraint table (bottom table). I explain what they mean, respectively, at times 2:39 and 9:04 in the video.

[@skkkylar]

very good!

[@Juan82777]

Brilliant

[@nadimkhan9731]

Hi

[@TallysYunes]

Hello!

[@PalakpreetKaur-jb8mw]

🙌🏻🤌🏻

[@zhitaolai2289]

shuan q😀

[@suryaramesh152]

So good ! Thank you so much

[@TallysYunes]

You're welcome!