OMIS355 homework

[Gabriel Bowers]

Anyone interested in tackling the current assignment at Lucas Hall either tonight or on Saturday afternoon?

My preference would be Saturday from ~noon with the goal of finishing within about 2 hours or tonight sometime after 7pm.

Gabriel

[Rachna Patel]

I can only make it sunday, let me know if anyone can do afternoon

--
Sent from my mobile device

[Almitra]

I am planning to be at school on Sunday afternoon..can't make it on Saturday.
--Almitra

[Carey Deangelis]

I was planning to come to campus on Sunday.  Almitra and Rachna do you want to meet on the 1st floor of Lucas at one of those tables at like 1 or noon?

- Carey

[Gabriel Bowers]

I will be in China Sunday onwards so I can make it.

[Rachna Patel]

Sure I can meet prob around 2

[Manuel Severino]

Unfortunately, I won't be able to meet between now and then. I think the email discussions could help in addition to any meeting you guys plan.


Manny

[Chase Morgan]

I'm in the same boat as Manny.

[Almitra]

I can meet around 2 too..,

[Subramaniam Narayanan]

I can try to meet Sunday afternoon after 2pm...

[Manuel Severino]

For those that have started on Prob 6, I got a solution of $9, 745,198.84 as the "e" or profit.

Anyone else get the same or different?


Manny

[Subramaniam Narayanan]

I am getting:

10,848,987.10

Did you use 18 as the number of chips that is produced after wafer processing? Here are my results for the decision vars:

X1     1100 

X2     19800 

X3     1741.935484 

X4     1741.935484 

X5     18058.06452 

X6     0 

X7     1313.364055 

X8     1100 

X9     0 

X10   428.5714286  

[Subramaniam Narayanan]

I reworked the problem as I got PC/laptop prod not having a corresponding sales activity. I am attaching my problem setup. Now I am getting:

e = 9573987.10

X1     1100 

X2     19800 

X3     1741.935484 

X4     1741.935484 

X5     18058.06452 

X6      0 

X7     1241.935484 

X8     1100 

X9     166.6666667 

X10    333.3333333  

Anyone else getting a different answer or a different problem setup?

[Darren Ng]

You didn't include X11 (PC's sold) and X12 (laptop sold), was that on purpose? Was it built into your model? I included them and got a different answer from both you and Manny...but I think mine is incorrect

[Subramaniam Narayanan]

I included X11(PC's sold) and X12(laptop sold) in my prev email attachment. What does your problem setup matrix look like?

[Subramaniam Narayanan]

I did some more checking. There was one line item that I had confusion on that caused my answer to be different than Manny. The line item was related to the wafers. I had the wafers as 2 constraints as:

X1 - X8 <= 0   wafers transfer row

X8 <= 1100    wafer purchasing capacity

If I changed these to

X1 - X8 <= 1100 an run the solver, I now get the same answer as Manny: $9, 745,198.84

I now think $9, 745,198.84 is indeed the correct answer. 

Thanks

- Narayanan

[Darren Ng]

OK... yea, I set mine up to have X1-X8 <=1100 and included X11 and X12. Now I get the same answer as Manny as well. e=$9,745,198.84.

That answer makes sense to me

[gtak...@yahoo.com]

X1 - X8 <= 1100

Move X8 to the right hand side
X1 <= 1100 + X8
"The # of wafers we process cannot exceed 1,100 plus the # of wafers
we purchase."
This would suggest we have 1,100 in beginning inventory and can buy
however much we want. Is that really the case?

Why might that approach be better than Narayanan's original one?
X1 <= X8 "We cannot process more wafers than we bought."
X8 <= 1100 "We cannot purchase more than 1,100 wafers."

On Nov 5, 8:46 pm, Subramaniam Narayanan <ssnarayan...@gmail.com>
wrote:

> I did some more checking. There was one line item that I had confusion on
> that caused my answer to be different than Manny. The line item was related
> to the wafers. I had the wafers as 2 constraints as:
>
> X1 - X8 <= 0   wafers transfer row
> X8 <= 1100    wafer purchasing capacity
>
> If I changed these to
> X1 - X8 <= 1100 an run the solver, I now get the same answer as Manny: $9,
> 745,198.84
>
> I now think $9, 745,198.84 is indeed the correct answer.
>
> Thanks
> - Narayanan
>
> On Sat, Nov 5, 2011 at 9:26 PM, Subramaniam Narayanan <
>
>
>
>
>
>
>
> ssnarayan...@gmail.com> wrote:
> > I included X11(PC's sold) and X12(laptop sold) in my prev email
> > attachment. What does your problem setup matrix look like?
>

> > On Sat, Nov 5, 2011 at 5:00 PM, Darren Ng <darren...@gmail.com> wrote:
>
> >> You didn't include X11 (PC's sold) and X12 (laptop sold), was that on
> >> purpose? Was it built into your model? I included them and got a different
> >> answer from both you and Manny...but I think mine is incorrect
>

> >>>>>> On Thu, Nov 3, 2011 at 3:34 PM, Almitra <karnik.almi...@gmail.com>wrote:
>
> >>>>>>> I can meet around 2 too..,
>

> >>>>>>> On Nov 3, 2011, at 1:31 PM, Rachna Patel <rachna.r.pa...@gmail.com>

> >>>>>>> wrote:
>
> >>>>>>> > Sure I can meet prob around 2
>

> >>>>>>> > On 11/3/11, Carey Deangelis <carey.deange...@gmail.com> wrote:
> >>>>>>> >> I was planning to come to campus on Sunday.  Almitra and Rachna
> >>>>>>> do you want
> >>>>>>> >> to meet on the 1st floor of Lucas at one of those tables at like
> >>>>>>> 1 or noon?
>
> >>>>>>> >> - Carey
>
> >>>>>>> >> On Thu, Nov 3, 2011 at 12:53 PM, Almitra <
> >>>>>>> karnik.almi...@gmail.com> wrote:
>
> >>>>>>> >>> I am planning to be at school on Sunday afternoon..can't make it
> >>>>>>> on
> >>>>>>> >>> Saturday.
> >>>>>>> >>> --Almitra
>
> >>>>>>> >>> On Nov 3, 2011, at 12:49 PM, Rachna Patel <

> >>>>>>> rachna.r.pa...@gmail.com>

> >>>>>>> >>> wrote:
>
> >>>>>>> >>>> I can only make it sunday, let me know if anyone can do
> >>>>>>> afternoon
>

[Subramaniam Narayanan]

Excellent point! When I see the 2 wafer constraints the way you put it, it seems that using:
X1 <= X8
X8 <= 1100
is the right approach. I had originally thought of the prob like that. We do not have a beginning inventory of 1100 wafers. We have a limit of purchasing 1100 wafers. That would imply we need separate constraints.

What do you think?

[Manuel Severino]

I agree folks. Great insight Greg!

I get $9,573,987.10 which is the same answer Subramaniam got.

Anyone  get this answer?


Manny

[gtak...@yahoo.com]

I'm gonna bank on that answer also.

Everybody, if you need a visual of what's going on (my .jpgs are fast
to download), I uploaded my answers and explanations on:

www.goofyconsulting.com

On Nov 6, 12:49 pm, Manuel Severino <manny.sever...@gmail.com> wrote:
> I agree folks. Great insight Greg!
>
> I get $9,573,987.10 which is the same answer Subramaniam got.
>
> Anyone  get this answer?
>
> Manny
>
> On Sun, Nov 6, 2011 at 5:22 AM, Subramaniam Narayanan <
>
>
>
>
>
>
>
> ssnarayan...@gmail.com> wrote:
> > Excellent point! When I see the 2 wafer constraints the way you put it, it
> > seems that using:
> > X1 <= X8
> > X8 <= 1100
> > is the right approach. I had originally thought of the prob like that. We
> > do not have a beginning inventory of 1100 wafers. We have a limit of
> > purchasing 1100 wafers. That would imply we need separate constraints.
>
> > What do you think?
>

[Rachna Patel]

Can't figure out what I'm doing wrong. Can anyone help? Attached is my excel doc. Thanks!

[Subramaniam Narayanan]

Hi Racha,

Double check your LHS column(Col M) in the spreadsheet. Instead of

=SUM(SUMPRODUCT(A6:M6,A$4:M$4))

you should have

=SUM(SUMPRODUCT(B6:M6,B$4:M$4))

for all the entries in that col. (Meaning A should be replaced with B)

Also check the cell O20 for the correct formula...

Thanks

- Narayanan

[Rachna Patel]

Thanks for looking into this. I fixed it, but unfortunately that doesn't change my values.

[Subramaniam Narayanan]

There was one more place where in the wafers constraints for the transfer row, the LHS should be 0 and not 1100. I think row 8, if you can check that as well...

[Rachna Patel]

got it! that did the trick -- thank you!

[Rachna Patel]

Anyone complete #5 to compare?

[Gabriela Tchaga]

here is my solver for problem 5

--
Gabriela G. Tchaga
GGTc...@gmail.com
510-386-5619