Potential exam questions Flashcards
A computer company has an annual demand of 10.000 units. They want to determine the EOQ, with an annual holding cost of $6 per unit and an ordering cost of $75. The lead time is 5 days, and the company operates 250 days per year.
Calculate: EOQ, TC & R
Solutions:
1) EOQ = 500u/order
2) TC = $3000
3) R = 200u
HP produces its premium plant food in 60lbs bags. Demand is 150.000 units per week. HP operates 50 weeks per year and can produce 250.000 units per week. The setup cost is $200 and the annual holding cost is $0.55/bag. Currently, HP produces its premium plant food in bags of 1.000.000lbs.
Calculate: MAXIMUM INVENTORY LEVEL (i max) & TOTAL ANNUAL COSTS of this policy
Solutions:
1) i max = Q(1-(d/p)) = 1.000.000 (1-(150.000/250.000)) = 400.000lbs
2) TC = (i max/2)H + (D/Q)S = $3.333
*** H = 0.55/60 because it is in lbs, we have to pass it to lbs
What is the hawthorne effect?
Is an effect discovered in the 1930s, indicates that productivity increases if workers are given attention.
What is the Krajlic Matrix? Explain its components
The Krajlic matrix helps companites to classify products into categories, is a matrix whose x-axis is supply risk, and its y-axis is profit. These 4 categories are essentially:
1) Non-critical
2) Leverage
3) Bottleneck
4) Strategic
What is JIT? Its benefits?
JIT (just-in-time) philosophy essentially consists of: getting the right quantity at the right place at the right time, eliminate the waste activities and surronding the entire organisation (=lean production).
Its benefits are the following:
- Inventory reduction
- Quality improvement
- Short lead times
- Lower production costs
- Increased productivity
- Increased machine utilization
- Great flexibility*
What document has all material requirements in it?
BOM (Bill of Materials) is a crucial input for MRP because it identifies:
- What materials are required
- Quantity needed
- Sequence in which they are used
What is an order qualifier? And an order winner?
Order qualifiers are the minimum criteria needed to compete.
Order winners are the features that set a product apart.
Today’s order winners may be order qualifiers in the future.
What are the 4 a’s of sustainable transportation?
They are these 4 (MASC):
▪ Vermeld (Measure)
▪ Vermijd (Avoid)
▪ Verschuif (Shift)
▪ Verschoon (Clean)
What are the 5 competencies of quality for manufacturing? And service quality?
- Manufacturing quality ➔ Focuses on tangible product features
- Conformance
- Performance
- Reliability
- Features
- Durability
- Service quality ➔ Focuses on the experience
- Intangible factors
- Consistency
- Responsiveness
- Courtesy, friendliness
- Promptness, timeliness
- Atmosphere
What is the formula for correlation coefficient?
𝑟 = 𝑛(∑𝑋𝑌) − (∑𝑋 ∙ ∑𝑌) / [sqrt( 𝑛∑ x^2 − (∑ 𝑋)^2)] ∙ [sqrt( 𝑛∑𝑌^2 − (∑𝑌)^2)].
▪ Correlation coefficient r close to 1 or -1
➔ Strong positive resp. negative linear relationship between X and Y
▪ Squared correlation coefficient 𝑟2 close to 1
➔ Regression line fits the data well
Which charts are there? Say each formula just to reminder if exercises will be taken.
- Control limits for x-bar charts:
𝑈𝐶𝐿 = 𝑥̿ + 𝑧𝜎𝑥̅
𝐿𝐶𝐿 = 𝑥̿ − 𝑧𝜎𝑥̅
- With 𝜎𝑥̅ = 𝜎/√𝑛 - Control limits for x-bar charts using sample
range as estimate of variability:
𝑈𝐶𝐿 = 𝑥̿ + 𝐴2𝑅̅ (3-sigma control charts bc there is R and 𝑥̿)
𝐿𝐶𝐿 = 𝑥̿ − 𝐴2𝑅̅ - Control limits for R-charts:
𝑈𝐶𝐿 = 𝐷4𝑅̅
𝐿𝐶𝐿 = 𝐷3𝑅̅ - Control limits for p-charts:
𝑈𝐶𝐿 = 𝑝̅ + 𝑧𝜎𝑝
𝐿𝐶𝐿 = 𝑝̅ − 𝑧𝜎𝑝
- With 𝜎𝑝 = sqrt(𝑝̅*(1−𝑝̅)/𝑛) - Control limits for c-charts:
𝑈𝐶𝐿 = 𝑐̅ + 𝑧√𝑐̅
𝐿𝐶𝐿 = 𝑐̅ − 𝑧√𝑐̅
- A manufacturer of printed circuit boards uses exponential
smoothing with trend to forecast monthly demand of its product.
At the end of December, the company wishes to forecast sales for
January. The estimate of trend of December is equal to 200
additional boards sold per month. The forecast for December
was 1000 units. The actual demand for December was 1100
units. The company uses 𝞪= 0.20 and 𝞫= 0.10. Make a forecast
including trend for the month of January.
The result is 1378.
FIT jan = F jan + T jan
F jan = 0,2 * 1100 + 0,8 * FIT dec (1000 + 200) = 1180
T jan = 0,1 * (1180-1100) + 0,9*200 = 198
1180 + 198 = 1378u.
[𝐹𝐼𝑇𝑡+1 = 𝐹𝑡+1 + 𝑇𝑡+1
𝐹𝑡+1 = 𝛼𝐴𝑡 + (1 − 𝛼)𝐹𝐼𝑇𝑡
𝑇𝑡+1 = 𝛽(𝐹𝑡+1 − 𝐹𝑡) + (1 − 𝛽)𝑇𝑡]
In the context of Danone, explain how the company might use forecasting models to improve its operations.
Danone uses forecasting models to predict demand for its products, improving production planning and reducing waste by aligning supply with customer demand.
Define SCM and explain the supply chain
SCM is the coordination and management of all the
activities of the supply chain ➔ prime example of OM
Hint: Supply chain consists of the network activities to deliver a finished product to a customer. (Supplier➔Manufacturer➔Distributor (e.g. MANN-FILTER)➔Retailer (e.g. AD)➔Customer)
