assignemts of operation mamagment.edited

8/13/2019 Assignemts of Operation Mamagment.edited

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Operation Management

Critical path methods

Introduction:

We have selected marble factory for applying critical path methods concepts. In this business

there are many process involves in cutting of marble pieces.

1. Oder of raw material to supplier.2. Unloading of raw material.3. Transfer of raw material from stocks to section machine.4. Transfer of marble pieces from section machine to small cutting pieces machine.5. Transfer of marble pieces from small cutting pieces to polishing machine.6. If special cutting machine.7. Shifting final marble piece into finished goods store.8. Finished marble piece sending to customers.

Explanation of business process:

1. Oder of raw material to supplier:In 1

ststage of this business they first place order of raw material. They are purchasing

raw material from different areas of (KPK) and Karachi. If they purchase Raw material

from Swat or Sawabi it takes one or two day to reach in factory.

If they buy raw material from Karachis suppliers then this order takes 3 or 4 days to

reach in factory.

2. Unloading of raw material:When consignment of raw material reaches in factory .the management hires 4 or 5

labors for unloading of stock. They unload one truck of raw material within 4 r 5 hours.

3. Transfer of raw material from raw material stocks to section machine:In this step factorys permanent employed labor are used for shifting raw material from

stock to Section machine. Section machine is used to convert big blacks into small

blacks. At this machine train labor is employed.


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4. Transfer of marble pieces from section machine to small cutting pieces machine :In this stage helping labor are used to shift material from section machine to othermachine. When section completes its work of cutting big block in to small blacks then

these small black shifted to small cutting machine for converting into one by one pieces

. At this machine one skilled is labor is employed some he works for fixed salary and

some works for extra time and get wages according to work which he has performed.

5. Transfer of marble pieces from small cutting pieces to polishing machine When small black have been completed then these blocks shifted to polishing machine

or designing machine. If special designing is not required then these marble tiles shiftedpolishing machine. If in the case if polish is not required then these marble directly

transferred to finished good stock.

6. If special cutting machine:When small cutting machine completes its work then these pieces can be shifted to three

places like one special cutting machine, polishing machine or finished goods store. If special

design is required for any order then required pieces are shifted to special cutting machine.

At special cutting machine there one of experience and skilled labor is employed for

designing.

7. Shifting final marble piece into finished goods store:When all types of work done on the marble pieces at all stage then these pieces are shifted

to finished goods stocks.

8. Finished marble piece sending to customers:At the last stage of process the finished goods are delivered to customers. Here helping labor

are used for uploading finished goods on truck.


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Activity list for the Darya marble factory project:

Activity Activity Description Immediate

predecessor

Completion

time(Hrs)

A Oder of raw material to supplier. - 96

B Unloading of raw material. A 3

C Transfer of raw material from stocks to sectionmachine.

B 24

D Transfer of marble pieces from section machineto small cutting pieces machine.

C 8

E Transfer of marble pieces from small cuttingpieces to polishing machine

D 72

F special cutting machine D 6

G Shifting final marble piece into finished goodsstore.

E,F 1

H Finished marble piece sending to customers G 1

Darya marble Critical path method of Graph:

A [0-96 ] B [96-99] C [99-123] D [123-131] E [131-203] G [203-204] H [204-205]

96[0-96] 3 [96-99] 24[99-123] 8 [123-131] 72 [131-203] 1 [203-204] 1[204-205]

F [131-137]

6 [131-137]

1 2 3 45 6

7

9


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Critical path:

In this project all the activities threaded as critical point from point A, B, C, D, E F,

G and H.

Tabulate ES, EF, LS, LF, and Slack time:

Activity Earliest

Start

(ES)

Latest

Start

(LS)

Earliest

Finish

(EF)

Latest

Finish

(LF)

Slack

(LS-ES)

Critical

Path

A 0 0 96 0 0 Yes

B 96 96 99 96 0 yes

C 99 99 123 99 0 Yes

D 123 123 131 123 0 Yes

E 131 131 203 203 0 Yes

F 131 131 137 137 0 Yes

G 203 203 204 204 0 Yes

H 204 204 205 205 0 Yes

Uncertain activity time:

Once we have established a network for project, we will need information on the

time required to complete each activity. This information will be used in

calculation of the duration of entire project and scheduling of specific activities.

Manager has experience and historical data necessary to provide accurate activity

tine estimate.

In order to incorporate uncertainty activity time into the network analysis, we will

need to obtain three time estimates for each activity. The three estimates are


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Optimistic time (a) The Activity time if everything progresses in ideal time. Most Probable time (m) the most likely activity time under normal

conditions.

Pessimistic time (b) the activity time if encourage significant breakdownand/or delays.

The three Estimates enable the manger to develop a best guess of most likely

activity time and then express the uncertainty by providing the estimate

ranging from best possible (optimistic) time to worst possible (pessimistic)

time.

Table:

Optimistic, Most Probable, and pessimistic Activity time Estimated (In Hours) for Darya

marble factory project.

Activity Optimistic

(a)

Most probable

(m)

Pessimistic

(b)

A 48 96 144

B 2 3 4

C 16 24 30D 6 8 10

E 48 72 96

F 4 6 8

G 0.5 1 2

H 0.5 1 2


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Variability of project completion Time:

In carrying out the critical path calculation, we treated the activity time as fixed at their

expected value; we are now ready to consider the uncertainty in the activity time and

determine the effect this uncertainty or variability has on the project completion date. Recall

that the critical path determines the duration of entire project.

For Darya marble factory project the critical path A, B, C, D, E, F, E, G and G resulted expected

project completion time of 205 hours.

Expected time formula T=a+4m+b/6

Table of Expected time and variation

Activity Expected time Variance

A 96 256

B 3 0.11

C 23.67 5.44

D 8 0.44

E 72 64

F 6.5 0.44

G 1.08 0.0625

H 1.08 0.0625

assignemts of operation mamagment.edited

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