NCC Skill Bulding

8/4/2019 NCC Skill Bulding

http://slidepdf.com/reader/full/ncc-skill-bulding 1/11

2. At what time of the day ( Clock time) do trucks start to queue up?

Therefore, it will take 3600

1200

Ans The truck will begin queueing at 11:00.

3. At what time of the day ( clock time) can the last truck leave?

6400 bbls - 3600 bbls

Ans Therefore, the last truck can leave at 16:00 + 3.5 = 19:30 O'clock

4. What is the average ( long term) inventory of berries in the holding bins?

Time Hrs Ave of each hr during this intervalTotal in this interval

8:00 - 11:00 3 1800 5400

11:00 - 19:30 8.5 3600 30600

19:30 - 24:00 4.5 1800 8100

24:00 - 08:00 8 0 0

Total 44100

Ave.Inventory in Bins = 44100

24

(3600+0)/2 =

0 =

The plant stop working at 20:00. However, wet berries cannot be stored overnight. So, during 20:00 to 24:00

working

800 bbl/hr= 2 hrs

The truck will queue up when the barrels of berries is reached the capacity of bins -- 3,600 bbls. The wet berri

1200 bbl/hr

= 3 Hrs

The last truck can leave when all berries are stored only in the bins or when the inventory of berries goes do

= 1,837.50 bbls

(0+3600)/2 =

(3600+3600)/2 =

NCC Skill Buildin206562 Production Planning and Inventory Control ( IE)

Pornpunsa Wuttisanwattana

Every day trucks carrying wet berries arrive uniformly over an 8 hour interval ( between 8 am and 4 pm) to a be

bbls per hour. The berries are dumped into holding bins with a storage capacity of 3,600 bbls, and trucks start qu

bins are full. The plant starts to process berries, according to the FIFO ( first-in-first-out) protocol, sharply at 12 n

bbls per hour, Berry processing continues till all berries that arrived are processed. The scenario described above r

1. Draw an inventory buildup diagram that shows total berry inventory in the system ( bins and trucks) starting at 8

the following day.

0

4800

6400

3200

0 00

1000

2000

3000

4000

5000

6000

7000

8:00 12:00 16:00 20:00 24:00 8:00

Buildup Inventory

Plant Start Plant StopTruck Start Truck Stop



5.What is the number of trucks waiting at 6 pm?

at 6 pm the total quantity on truck is

= Q at 4 pm - Produced berries from 4-6 pm - bin capacity

= 6400bbls - 2hr(800 bbls/hr) - 3600 bbls

= 1200 bbls

Average 100 bbls / truck

There are 1200/100 = 12 Trucks are waitng.

Arrival rate 1200 bbl/hr or 12 Trucks/hr

During 8 hours interval, total arrived trucks 96 Trucks

Trucks arriving before the bins are full do not have to wait.

From Question 2.,The bins are full at 11:00. So any trucks arrives at 8:00 - 11:00 ( 3 hours) does not have to w

Ans that is 3 hrs * 16 trucks.hr = 36 Trucks Do not need to wait

And the rest 96 - 48 = 60 Trucks Have to wait

7. What is the total waiting time (in hours) of trucks?

Total truck waiting hours = Q of waiting berries

Waiting berries = area above bin capacity

= 1/2*1*(4800-3600)+(4800-3600)*4+1/2*4*(6400-4800)+1/2*1.5*(6400-3600)

= 10700 bbls . Hr

Ans Total truck waiting hours is 107 Truck . Hrs

8. Consider on the trucks that have to wait. How long does such a truck have to wait on the average?

From Problem No. 6 -7

60 trucks have to wait and total of waiting time for all waiting trucks is 107 truck. Hr

Ans Therefore, Each waiting truck waits for 1.8 hours or 1 hour 48 mins

9. What is the maximum number of trucks waiting at any point in time?

The number of trucks will be maximum at 16:00. At this time quantity of berries on the truck is

= Total Berries at 16:00 - Bin capacity

= 6400-3600 = 2800 bbls

Ans Therefore , Maxinum No. of trucks is 28.0 trucks

10. What is the maximum amount of time any truck has to wait?

The trucks that have to wait longest is the last truck that arrives.

Ans From question No.3, the last truck will have to wait 3.5 hours.

At 14:00 the Q on truck is Q at 12:00 + 2hr*400bbl/hr - bin capacity

= 4800+2*(400)- 4800 = 800 bbls

therefore, Truck will have to wait 1 hr

At 15:00 the Q on truck is Q at 12:00 + 3hr*400bbl/hr - bin capacity

= 4800+3*(400)- 4800 = 1200 bbls

therefore, Truck will have to wait 1.5 hr

Ans Average truck waiting time between 2 pm to 3 pm is 1.25 hrs

6. Of all the trucks that arrive what is the number of trucks that do not have to wait at all? What is the number of tru

11. Consider a truck that arrives between 2 pm and 3 pm. How long does such a truck have to wait on average?

Given : Bin Capacity is 4800bbls

Average Berries Quantity that store on the truck between 2- 3 pm is the area under curve between 2 - 3 pm wh

capacity of 4800 bbls



12.What is the maximum time any truck has to wait? Given : Bin Capacity is 4800bbls

Ans The trucks that have to wait longest is the last truck that arrives.

The Maximum quantity - Bin capacity

6400 bbls - 4800 bbls

The maximum time that truck has to wait is 2 hrs

When Holding bins capacity is 4,800 bbls and after 16:00 Plant capacity is 400 bbls/hr

13. What is the average waiting time (in hours) of trucks?

Total Berry quantity waiting is the quantity above 4800 bbls

= 1/2 * (20-12) * (6400-4800)

= 6400 bbls.hr

Or 64.00 Truck .hr

Trucks arrives 1200 bbls/hr or 12 Truck/hr

During 12:00 - 16:00 ( the interval that the Q is above bin capacity), 4 hours

there are 48 Trucks

The average waiting time is total truck waiting time/ total truck waiting is

Ans 1.33 hrs or 1.00 hrs 20 mins

14. What is the maximum time any trucks has to wait?

Ans The trucks that have to wait longest is the last truck that arrives.

The Maximum quantity - Bin capacity

6400 bbls - 4800 bbls

The maximum time that truck has to wait is 4 hrs

= 4 hrs400 bbl/hr

Plant capacity

= 2 hrs800 bbl/hr

Plant capacity

0

4800

6400

4800

3200

1600

00

1000

2000

3000

4000

5000

6000

7000

8:00 12:00 16:00 20:00 24:00 04:00 8:00

Buildup Inventory



Due on August 1,11

ill be Overtime

s arrive at the rate of

n to 3600 bbls.

rry arrival rate is 1,200

ueing up as soon as the

on at the rate of 800

peats itself every day.

am and ending at 8 am



ait

ck that have to wait?

ich is above bin





Time bbls

8:00 0

12:00 4800

16:00 6400

20:00 3200

24:00 08:00 0

Time bbls

8:00 0

12:00 480016:00 6400

20:00 4800

24:00 3200

04:00 1600

8:00 0

Time bbls

8:00 0

12:00 4800

16:00 6400

20:00 4800

24:00 3200

04:00 1600

8:00 0

0

4800

6400

4

0

1000

2000

3000

4000

5000

6000

7000

8:00 12:00 16:00 20:00

Buildup Inve



Time bbls

8:00 0

12:00 4800

16:00 6400

20:00 4800

24:00 3200

04:00 16008:00 0



00

3200

1600

0

24:00 04:00 8:00

tory



3600 1800 3 5400

7600 3800 1 3800

8000 4000 1 4000

10000 5000 4 20000

6000 3000 10 30000

0 0 5 063200

2633.333

100 15

50 15

1 0.5 1 1200 600 50 15

2 0.5 1 400 200

3 1 1 1200 1200

4 1 1 1600 1600

5 1 7.33 1600 117286 0.5 4 2000 4000

7 0.5 3.33 2000 3330

0.5 2.667 1600 2133.6

24791.6



6.666667 7

3.333333 4

3.333333 4

16.8157 3.2612 3.2612 23.3381

2.6378 0.6494 0.6494-14.1779 -2.6118 -2.6118

0.8877 0.1842 0.1842

0.3467 0.1842 0.1842

0.1404 0.1842 0.1842 0.5088

-0.2063 0 0

Documents

NCC Skill Bulding