counterweight/aoml
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Small changes to case 1.

Browse source
This commit is contained in:
pablo 2022-04-18 11:57:35 +02:00
parent 6c3625ac05
commit f587f2dd0f
1 changed files with 41 additions and 37 deletions
Download patch file Download diff file Expand all files Collapse all files

78
cases/case_1/case_1_description.md
View file

@ -53,27 +53,29 @@ view, they are usually just called "the clients". Whenever one of the clients
needs raw beans, they arrange a transport truck that goes to the warehouse to
pick up a certain amount of goods. Elisa's team fills up the truck with the
requested goods, and then the clients take care of receiving that at their own
locations.
locations. Given the size and relevance of the Caserta warehouse, activity is
pretty much constant, with goods leaving the warehouse towards client locations
every day.
The Caserta warehouse itself has only one way to source coffee beans to store
in their warehouse: requesting them to the Beanie Limited central offices in
Diemen, near Amsterdam. Whenever Elisa's team considers that more stock is
needed, they post a sourcing order to the central office for a certain amount
needed, they post a Purchase Order to the central office for a certain amount
of beans. The central office arranges the goods and the delivery and, after a
few days, the goods reach Caserta and are stored. The central office tries to
ensure a lead time of 7 days (lead time is the time that passes between an
order being placed and the goods reaching their destination), but the reality
is they do what they can and this time is not always respected.
few days, the goods reach Caserta and are stored in the warehouse. The central
office tries to ensure a lead time of 7 days (lead time is the time that passes
between an order being placed and the goods reaching their destination), but
the reality is they do what they can and this time is not always respected.
Stock is a necessary evil (it implies a lot of cost), but Elisa's warehouse
plays a key role in serving the clients in their region properly. Having too
little stock means the clients need to wait long times to get their goods,
which is risky for the business. On the other hand, having a lot of stock means
high warehouse costs and financial opportunity cost (if Beanie Limited has 1
million € in coffee beans in a warehouse, that is 1 million € they can't invest
somewhere else to improve their business). Thus, Elisa needs the stock to be as
small as possible, while making sure she is not disappointing clients at the
same time.
needs it to serve the clients in their region properly. Having too little stock
means the clients need to wait long times to get their goods, which is risky
for the business. On the other hand, having a lot of stock means high warehouse
costs and financial opportunity cost (if Beanie Limited has 1 million € in
coffee beans in a warehouse, that is 1 million € they can't invest somewhere
else to improve their business). Thus, Elisa needs the stock to be as small as
possible, while making sure she is not disappointing clients at the same time
because of stockouts.
Elisa is calling you because 2021 was a terrible year for the warehouse. The
year was a chaotic one, and Elisa's team was not able to run operations
@ -82,12 +84,12 @@ that the warehouse stock was unnecessarily high at times, and that there were
too many periods where the warehouse was out of stock and clients had to wait
to get their goods.
Elisa thinks that the main reason for this is the lack of a clear policy for
when to order and how much to order from Diemen. Her team decides independently
when to do it, and Elisa has a feeling that they are not approaching these
decisions the right way. This means that sometimes they order when there is no
need to, sometimes they don't order when they should be, and that the amounts
being ordered might not always be the best ones.
Elisa thinks the main reason for this is the lack of a clear policy for when to
order and how much to order from Diemen. Her team decides independently when to
do it, and Elisa has a feeling that they are not approaching these decisions
the right way. This means that sometimes they order when there is no need to,
sometimes they don't order when they should, and that the amounts being ordered
might not always be the optimal ones.
Here is where you come in. As simulation experts, Elisa expects from you that
you can help design an ordering policy to fix these issues. Doing this implies
@ -107,7 +109,8 @@ SimiUPF will be mad at you...
Level 4 is optional.
- You need to write a report document where you answer the questions of the
different levels. This report should be directed towards Elisa, should give
her clear recommendations and should justify these recommendations.
her clear recommendations and should justify these recommendations. It's
important for you to reflect your methodology to back your proposals.
- Each level is worth 2 points out of a total of 10. The 2 missing points will
grade the clarity and structure of your report and code.
- You need to use a Python notebook to solve all levels. A helper notebook is
@ -122,21 +125,23 @@ SimiUPF will be mad at you...
to serve clients. There is some amount leaving every day because the
warehouse serves many small orders from small clients, so there is always
some order being fulfilled. The amount is measured in kilograms, and
represents the total amount that left during that day.
- sourcing_events: this table shows the beans orders that Elisa's team
represents the total amount that left during that day. Individual orders
are not relevant for this case, so we only look at daily total figures.
- sourcing_events: this table shows the Purchase Orders that Elisa's team
placed to Diemen. For each order, there are two dates: the date when
Elisa's team placed the order, and the date where the beans actually
reached the Caserta warehouse. The amount is measured in kilograms.
reached the Caserta warehouse. The difference between those dates is the
real lead time of each order. The amount is measured in kilograms.
- stock_state: this table shows the stock at the warehouse at the end of
each date. As you can guess, the stock for a certain date is the stock of
the previous day, plus the goods that reached Caserta coming from Diemen,
minus the goods that left the warehouse to serve client orders. A
negative stock is not a challenge to the laws of physics: it means
clients are waiting for their requested beans. If one row shows -1.000,
it means that the warehouse is empty, and clients are awaiting for a
total amount of 1.000 kgs of beans. If next morning, a 1.000 kgs reach
Caserta from Diemen, those will be used immediately to satisfy those
waiting clients, and the warehouse stock will become 0.
it means that the warehouse is empty, and clients are awaiting a total
amount of 1.000 kgs of beans. If next morning, a 1.000 kgs reach Caserta
from Diemen, those will be used immediately to satisfy those awaiting
clients, and the warehouse stock will become 0.
## Notebook
@ -150,28 +155,27 @@ warehouse. The instructions on how to use the code are in the notebook itself.
- Elisa wants you to measure the performance of the last year, providing
quantitative metrics. She knows it was a bad year, but hasn't looked at
the real data to summarize how bad it was. Remember that there is a
trade-off:
too much stock, is not desired, but running out of stock and making
clients wait is also negative.
trade-off: too much stock, is not desired, but running out of stock and
making clients wait is also negative.
- Going one step further, Elisa wants to know: what was done wrong?
- Level 2
- Elisa wants you to propose an ordering policy. This means, that you need
to define a rule that, once each day, should answer the questions: should
be place an order to request material today? If yes, how much should we
order?
we place a Purchase Order to request beans from Diemen today? If yes, how
much should we order?
- Use simulation to present metrics on what is the expected performance
with the policy you are proposing. Remember, you need to convince Elisa
that this is better than what happens today.
- As a specific constraint, Elisa explains that she wants that the
probability of a stockout to be at most of 5% on any given day.
-
- Level 3
- Right after you finished designing your policy for level 2, Elisa called
with some news: she has just been informed by the management in Diemen
that a new Minimum Order Quantity (MOQ) rule will begin soon. This rule
means that, when the Caserta warehouse places an order to request
material from, the order should be of at least 500,000 kgs of beans, and
not less than that.
material from Diemen, the order should be of at least 500,000 kgs of
beans, and not less than that.
- Elisa wants you to take this into account. Does it affect the policy you
proposed for level 2? If so, you need to come up with a new one that
adapts to this rule and compare it to the previous one.
@ -186,7 +190,7 @@ warehouse. The instructions on how to use the code are in the notebook itself.
in exactly 15 days.
- Elisa would love if you could take some additional time to study this
proposal. What is better for Caserta? The current 7 days target
lead-time, with unstable deliveries? Or a fixed, 15-day lead time?
lead-time, with unstable delivery times? Or a fixed, 15-day lead time?
- The MOQ rule of level 3 still applies.