The MRP Crusade - Material Requirements Planning - MRP
21 important questions on The MRP Crusade - Material Requirements Planning - MRP
Why is MRP a push system?
MRP adds the link between independent and dependent demand and computes schedules of what should be started (pushed) into production based on demand
What is the difference between independent and dependent demand?
Independent demand is demand that originates outside the system.
Dependent demand is demand for components that make up independent demand products.
Name 2 types of orders and explain their difference.
1: Purchase orders: orders from outside the plant.
2: Jobs: orders from within the plant.
- Higher grades + faster learning
- Never study anything twice
- 100% sure, 100% understanding
For my 1st exam I got a C. Then, I started looking for ways to learn better and I came across Study Smart. Since then I have scored a A+, A, A- and another A. I highly recommend it to everyone who wants to hear it. I am so happy with it!!
I was struggling to finish all my first-year subjects for 3 years. Then I discovered Study Smart, which helped me to finish all of them within 3 months.
Because of StudySmart, things are going well in many ways. Before, I always had study stress and no time for anything. Now I feel calm and confident (because of the program). I used to score a B, now I usually score an A or A+.
Hey Chris, I really want to thank you very much for developing the platform, I usually got around C for my exams, now I scored an A+, an A and a A- !!
Since using Study Smart, my average has increased significantly. I even completed a statistics course with a A+ while I'm bad at statistics. I took on extra courses this year, because of Study Smart. Thanks so much!
Ever since I started studying with StudySmart I passed all my exams !!! No more re-sits!! At first, I was happy with a pass and now I only get good grades. Many thanks!
I aced all the courses I studied with Study Smart. For law, I first scored a D, and now an A! I’m 100% sure that I’ll pass all the courses I study with Study Smart.
I always thought I studied well. My grades were fine. I could never have imagined that applying these study skills would have such a huge and direct impact on my grades, my speed and the pleasure I have in learning.
For the first time, I finally feel totally confident about the way I learn. I have the perfect overview and make great progress in terms of speed and the grades I get. Thanks, Chris!
I immediately started to enjoy learning again, and my grades soared. All of a sudden, everything went better. I highly recommend Study Smart to all students..
Being able to create my materials online made the process of studying so much smoother and quicker. I no longer have to spend a huge amount of my time on creating my summaries.
At first, my notes were a mess. Now I use Study Smart to take my notes in a perfectly structured way. It helps me to save a lot of time and do other things I enjoy.
Students that study with Study Smart get better grades. The system applies all the learning methods in such a way that both well-performing students and students who struggle perform much better.
Hi Chris, I would like to thank you very much. Last year I scored C on a course, and this year I got an A+ thanks to your method! Thank you very much!
The largest effect is that my child is more enthusiastic about school! Every parent wants their children to be happy at school, Study Smart made it happen.
In high school, I failed several exams, and that has really changed now. I actually needed this tool very much back then. Since I started studying with StudySmart, I haven't had any D's. My average score is now an A and those are results I would have never had in the past
With my old method, I passed only 3 out of 8 courses. Since I started taking my notes digitally in Study Smart, I have passed all my courses on the first try. For me, StudySmart takes away the stress of wondering if I will pass or not.
Thanks to StudySmart, I passed all my exams, and with better grades than before! On top of that, I have mastered a very good study method now, which I am confident will help me earn my degree.
What is a bucket and what ''size'' is a normal one for it nowadays?
A bucket is an interval that is used to break time and demand into discrete parts. Most modern MRP systems use daily buckets.
Katy says: ''Since items with an LLC higher than 0 are not end items, their demand is always dependent.'' Steve thinks she is wrong. Who is right?
Steve is right. Every item with an LLC greater than 0 will have a big portion of dependent demand as it is an item in a(n) (sub)assembly. However, all items can have independent demand. I.e. as spare parts, needed in repairs etc.
What information on an MRP tableau stems from the MPS?
1: gross requirements
2: on-hand inventory
3: scheduled receipts
Which 5 steps are involved in the MRP procedure?
Starting at the items with an LLC of 0:
1: Netting; determining net requirements (subtracting on-hand inventory & scheduled receipts off the gross requirements)
2: Lot sizing; dividing the netted demand into appropriate lot sizes
3: Time phasing; offsetting the due dates of the jobs with lead times to determine start times
4: BOM explosion; use start times, lot sizes and BOM to generate gross requirements for items at the next levels
5: Iterate; repeat till all levels are processed
What are the basic inputs to MRP?
1: a forecast of demand for end items
2: BOM (bill of material)
3: current inventory status
4: any data to specify production policies
What are the MRP outputs?
1: planned order releases
2: change notices
3: exception reports
What is an FOP with P=1 equivalent to?
It is equivalent to the lot sizing rule 'lot-for-lot'.
What concept in an MRP tableau always goes with a change notice?
Adjusted scheduled receipts.
Why would a manager use "firm planned orders"?
To prevent the production schedule from becoming unstable. Firm planned orders reduce scheduling disruptions.
When using a safety stock of 20, is this stock added to or subtracted from projected on hand-inventory in an MRP tableau?
It is subtracted, see table 3.9 as an example.
What can be used as a protection against uncertainty in production and demand timing?
Safety lead time.
When a production system has long setup times and small buckets, which lot sizing rule becomes impractical?
Lot-for-lot.
Part-period balancing is a lot-sizing policy that balances:
A: setup time with order frequency
B: inventory-carrying cost with setup cost
C: setup cost with order frequency
B is correct.
True or false: ''Pegging should be used to protect against yield loss or fallout."
False. Pegging is used as a means of troubleshooting and is useful in bottom-up replanning (when a problem has already occurred). To protect against yield loss or fallout, using safety stock is a good measure.
True or false: "The average yield rate is not enough to determine an effective yielding strategy. The mechanism and variability of processing must also be considered."
True. For a good example check p. 135.
What are the 3 most severe problems with MRP?
1: Capacity infeasibility of MRP schedules.
2: Long planned lead times.
3: System "nervousness".
What does system nervousness mean?
It means that an MRP system can be susceptible to large changes in planned order releases when a small change in the MPS occurs. This can make some schedules suddenly infeasible.
Why did Orlicky (and the other originators of MRP) feel that statistical reorder point models were better suited to final products than components?
Demand for components is a function of demand for final products and is therefor known for any given assembly schedule. In other words: most demand for components is dependent.
The question on the page originate from the summary of the following study material:
- A unique study and practice tool
- Never study anything twice again
- Get the grades you hope for
- 100% sure, 100% understanding
