15
votes
Recommendations for OM blogs
Here is the list of blogs and social media that I regularly check [in no particular order]:
https://www.zverovich.net/
https://yetanothermathprogrammingconsultant.blogspot.com/
https://orinanobworld....
- 3,459
10
votes
What is the difference bewteen CP and MILP approaches in Job Shop Scheduling?
CP is not a subset of MILP. They are separate modeling/solving paradigms whose domains of application overlap. Both can solve for optimal solutions (in CP's case, by incorporating a constraint that ...
- 37.8k
10
votes
Good distribution assumptions for customer demand in a supply chain
I agree with @QianZhang's answer (nice theoretical properties, easy to implement), and I would add that there is some theoretical justification too. If demands come from customer arrivals, then ...
- 13.1k
9
votes
Is a "multistep" or "multiphase" Newsvendor model possible?
There are several models available to make the sort of decisions you are asking about. Most tend to make ordering decisions based on inventory level rather than on time: That is, they say things like "...
- 13.1k
9
votes
Good distribution assumptions for customer demand in a supply chain
In my understanding, using normal/Poisson distribution for customer demand is mainly for two reasons.
These distributions have nice properties for theoretical analysis in supply chain models
These ...
- 512
9
votes
Accepted
Supply Chain Public Data Repository
I was wondering if there is any repository of datasets for supply chain problems?
Global Garment Supply Chain Data - A collection of import data from various retailers - Last updated: October 19, ...
- 2,098
7
votes
Supply Chain Public Data Repository
Éric Taillard publishes problem sets for flow shop, job shop and open shop scheduling (from one of his papers) at http://mistic.heig-vd.ch/taillard/problemes.dir/ordonnancement.dir/ordonnancement.html....
- 37.8k
7
votes
Holding cost vs carrying cost vs storage cost
According to a buddy of mine who was a faculty member in the area of purchasing / sourcing / procurement (they change their name every few years), "holding cost" and "carrying cost" are used pretty ...
- 37.8k
7
votes
Holding cost vs carrying cost vs storage cost
I agree that holding cost, carrying cost, and storage cost all sound like the same thing. The only thing I will add to the answer by @prubin is that often holding costs are expressed as a percentage ...
- 13.1k
7
votes
Recommendations for OM blogs
For OM, you might like Jay, Barry and Chuck's OM Blog.
For OR, I like OR in Devon, UK as well as many of the entries in Richard's excellent answer. I had a few other OR blogs that I liked, but sadly ...
- 37.8k
6
votes
Recommendations for OM blogs
Our blog might be useful too:
https://www.optaplanner.org/blog/
We cover OR use cases (just did an article on Covid Appointment Scheduling), our technology and general insights.
- 4,717
6
votes
Accepted
An efficient method for zoning bins in a warehouse
Here is a reformulation as MIQP. Minimize
$$\sum_{i,j,j'} D_{jj'} x_{ij} x_{ij'}$$ subject to
$$\sum_i x_{ij} = 1 \quad \text{for all $j$} \tag1\label1$$
If both $j$ and $j'$ are assigned to the same ...
- 30.4k
5
votes
Recommendations for OM blogs
SAS (my employer) has several blogs. Here are two relevant tags:
https://blogs.sas.com/content/tag/optimization/
https://blogs.sas.com/content/tag/operations-research/
- 30.4k
5
votes
Accepted
Procurement and supply management: model-oriented undergradute textbook
I checked with a colleague who taught procurement / sourcing / purchasing / supply management / for quite a few years. He's skeptical about there being any heavily OR-oriented books in the field. ...
- 37.8k
4
votes
Buyback policy in a supply chain
In terms of the theory of buyback contracts (i.e., the math), it doesn't matter what the party doing the "buying back" (the manufacturer, in your question) does with the goods. They can resell them, ...
- 13.1k
4
votes
Buyback policy in a supply chain
Per my friend the procurement guru, buyback contracts are apparently rare, whether between retailer and wholesaler or between wholesaler and manufacturer. In any case, the options for the party buying ...
- 37.8k
4
votes
Approaches for choosing a "risk" factor in an Inventory Optimization problem?
Here's an approach that might be close to what you are looking for. Suppose that we have $n$ products, and for each product $i$ we know:
$c_i$ = purchase cost per unit (i.e., cost to order inventory ...
- 13.1k
4
votes
Good distribution assumptions for customer demand in a supply chain
Question: Why do we normally assume normal distribution/Poisson distribution for customer demand in a supply chain?
Answer :
Based on my experience in the industry, I have seen that generally, ...
- 81
4
votes
Advanced Transportation optimization problem
This sounds like a network optimization problem with inventory consideration. There could be two possible scenarios:
You have already determined the location of potential warehouses.
You'd like to ...
- 394
3
votes
What is a transport order in supply chain management?
According to a colleague in supply chain management (who is not 100% confident in his answer), the phrase "transport order" frequently (usually?) means an order to move stock from one ...
- 37.8k
3
votes
Improving Customer First Fulfillment Rate
Before asking if demand and lead time have a specific distribution (normal or other), you might want to ask whether they have stationary distributions or exhibit trend and/or seasonality. If the ...
- 37.8k
3
votes
What is the difference bewteen CP and MILP approaches in Job Shop Scheduling?
Google has a very nice library called OR Tools. One of those tools is a CP-SAT solver. Even though their solver works only on integer valued variables it is not that hard to convert MILP models to ...
- 341
3
votes
WIP Inventory Level Constraint?
What you are trying to do sounds like an MRP (material requirement planning) system. For this, you already need to define the component's precedence relations as a directed graph and apply the stages ...
- 8,390
3
votes
Good distribution assumptions for customer demand in a supply chain
Theoretically it is quite naturally convincing to assume that demand time points are independent. In other words knowing that an item was bought in t1 does not give ...
- 231
3
votes
Holding cost vs carrying cost vs storage cost
The unit of each cost shows the nature of that type of cost. With that, I mean if you look through the units, you can easily figure out whether:
The cost is fixed (it is independent of the inventory ...
- 8,622
3
votes
Transportation problem with consolidation within path
If your demands are per source-destination pairs, then you are very likely dealing with a variation of the multi-commodity flow problem, where each source-destination pair is a commodity.
The ...
- 12.9k
2
votes
Procurement and supply management: model-oriented undergradute textbook
If you are interested in supply chain management and its related processes, there are lots of textbooks which these concepts have been described in the mathematical form to illustrate and control the ...
- 8,390
2
votes
Is Multidisciplinary Design Optimization / Collaborative Optimization used anywhere outside of the Mechanical Engineering context?
As a student I am doing research in this field, I found Wikipedia's explanation very useful. You are right, most of the applications of MDO are in the field of design for aerospace and mechanical ...
- 8,622
2
votes
WIP Inventory Level Constraint?
I assume this is a multiperiod problem. Create a variable $I_{k,t}$ for the inventory of category of category $k$ material available to the second stage at the end of time period $t$. Production ...
- 37.8k
2
votes
Robust Optimization and Supplier Selection
RO is still in academic research area and several methods have been proposed. What I would do is this( not using any math programming model as you have already formulated already)
Solve for q=0
Solve ...
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