Production Planning and Control - Dec 2014
Mechanical Engineering (Semester 7)
TOTAL MARKS: 100
TOTAL TIME: 3 HOURS
(1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks.
Solve any four of the following:
1 (a) What are the different techniques of Shop Floor Control and how are they used to solve production problems?(5 marks)
1 (b) What are the seven wastages of JIT? How does the Kanban system help in applying JIT to any production process?(5 marks)
1 (c) Where does Bill of Material (BOM) figure in the MPC framework? Write about BOM and its usage in MPC.(5 marks)
1 (d) Write about the different aggregate planning strategies used by manufacturing companies for production of different components.(5 marks)
1 (e) Write about the various costs associated with inventory control.(5 marks)
1 (f) Create a MRP record and describe its various components.(5 marks)
2 (a) Four different types of jobs go through five machine in the order of Blanking?Piercing?Grinding?Soaking?Coating? (passing is not allowed). Find the optimal sequence where the processing times (in minutes) of each job at the different machines is given in the table below.
JOBS | ||||
MACHINES
Soaking |
1 6 4 1 2 8 |
2 5 5 3 4 9 |
3 4 3 4 5 7 |
4 7 2 2 1 5 |
Determine the total elapsed time and also find the idle time of each machine.(10 marks) 2 (b) A department head has 6 jobs and 5 workeRs. The workers differ in their efficiency and the job differ intrinsic difficulty. The department head estimates the time (in minutes) each worker would take to perform each job as given in the table below.
Worker | JOBS | |||||
P | Q | R | S | T | U | |
1 2 3 4 5 |
20 15 11 8 12 |
15 32 15 24 20 |
26 46 2 12 18 |
40 26 12 22 10 |
32 28 6 22 22 |
12 20 14 20 15 |
Only one job can be assigned to one worker. Determine how the jobs should be allocated so as to minimize the total work houRs. Also find total work houRs.(10 marks) 3 (a) The ABC company has recorded the following data for one of its new products over a six month period.
Month |
Demand (in units of product) |
Jan Feb Mar Apr May Jun |
40 70 60 120 100 90 |
i) What would the forecast be for all the months, if exponential smoothing method is used, with a=0.2 and forecast for January of 30 units.
ii) What would the forecast for May have been, if made at the end of April, using a four month moving average.
iii) What would be the mean absolute deviation (MAD) for all the six months using the forecasts obtained by the exponential smoothing method as used above.(10 marks) 3 (b) Solve the following problem by using the Big M method:
Maximum | Z=4x_{1}+5x_{2}-3x_{3} |
Subject to: | x_{1}+x_{2}+x_{3}=10 |
x_{1}-x_{2} ?1 | |
2x_{1}+3x_{2}+x_{3} ? 40 | |
x_{1}, x_{2}, x_{3} ? 0 |
Month | Jul | Aug | Sep | Oct | Nov | Dec |
Demand | 3500 | 3700 | 3900 | 4000 | 3400 | 3600 |
Working day | 25 | 23 | 21 | 24 | 23 | 22 |
production Details: Safely Stock of 200 units per month, Beginning inventory of 500 units, No. of workers is 20 labour hours required is 10 hr/unit, Materials cost is Rs. 100/unit, Inventory carrying cost is Rs. 100/unit/month, Cost of shortage is Rs. 200/unit/month, Cost of subcontracting is Rs. 500/unit, Hiring and training costs is Rs. 250/worker, Layoff cost is Rs. 400/worker, regular production time labour cost (first 8 hours)=Rs. 20/hour. Overtime cost is Rs. 30/hour.
Determine the total production cost of using constant workforce and using subcontracting only and not carrying forward any excess inventory (include material production costs also).(10 marks) 5 (b) create the MRP plan (8 weeks) for the production of a component with the requirements shown below.
Let size=200 units and lead time of 1 week and safely stock=zero units.
weekly requirements: week 1=50 units, week 2=150 units, week 3=180 units, week 4=80 units, week 5=12.0 units, week 6=220 units and week =150 units.
Inventory on hand = 210 units
If the inventory on hand changes to 60 units and a scheduled receipt of 100 units is expected to arrive in week 2, redraw the MRP plan and recalculate the table.(10 marks) 6 (a) Describe all the aspects of capacity planning with reference to MPC.(10 marks) 6 (b) The ford car company has three plants at locations in Chennai, Naida and Hyderabad which supply to warehouses in Delhi, Mumbai, Kolkata, Nagpur and Bangalore. Monthly plant capacities are 800, 500 and 900 units. Monthly warehouse capacities are 400, 400, 500, 400 and 800 units respectively. Unit transportation costs (in Rs.) are given below.
Delhi | Mumbai | Kolkata | Nagpur | Bangalore | |
Chennai Noida Hyderabad |
8 4 8 |
8 7 4 |
6 7 6 |
6 6 6 |
3 5 4 |
Determine an optimum distribution for the company in order to minimize the total transportation costs.(10 marks) 7 (a) For the project tasks given below, draw the complete network and determine the critical path and its duration Also find the value of total floats for each activity.
Activity | A | B | C | D | E | F | G | H | I | J | K | L | M | N |
Preceding Activity |
- | - | - | A | A |
B, D |
C | A | C | C |
E, F, G |
H, I |
L |
J, K |
Activity Duration |
3 | 5 | 6 | 7 | 4 | 2 | 4 | 6 | 5 | 7 | 4 | 6 | 3 | 3 |