Lecture 20D

Question 1

We use simulation techniques to model activities on the site like crane movement load…..

Answer 1

true

Question 2

What we want to do is graohical representation of the tasks when they are going to take place

Answer 2

WE want to have the schedule

Question 3

we said to get to that we break down the WBS to get set of activities
Next we study the sequencing , which is the predecessor of which (types of dependedncies, finish to start…..lag)
Then i start deriving the schedule if i Know the duration of work

Answer 3

true

Question 4

Determining duration

Answer 4

What affect duration of work

DUration is driven by productivity and quantity of work

Question 5

Productivity is affected by several factors:

Answer 5

Weather
Experience of workers
Resources time (Equipments productivity)
Method of work (More strict tolerances , more time doing the work)
Working hours schedule (how many hours and days people work)]
method of statement
crowdiness

Question 6

Working double shifts (like having 2 crews one from 8 to 5 and one from 5 to 2 am) affect productivity because of the handover

Answer 6

true , each crew have to figure what the other crew did

Question 7

Working during night times is less productive than day times

Answer 7

true

Question 8

The formula to get the duration is simple

Answer 8

quantity of work / productivity

We express productivity per crew not per worker, because work is done by crew

Question 9

The difficulty is to get the productivity

Quantity u get it from BOQ, it is usually up to 10 percent exact

Answer 9

Productivity s diffficult to get because of all the factors mentioned above
For example in lebanon, now we get strikes , which will affect productivity…many things psychological

Question 10

So in order to get productivity we make assumptions

Answer 10

We assume it determinstic and constant
( I think of all what i have factors that afffcect my productivity and I deduce a productivity like 10 units per day per crew)

Question 11

Most schedules are developed using single points estimates of productivity

Answer 11

true

this is a big assumption

Question 12

If i have a problem in productivity, I may have problems at the individual levels so ilook there and analyze also there might be other problems

Answer 12

true

Question 13

productivity starts lower at fisrst then improve in repetiitive acts

Answer 13

like the crew installed 2st window in 4 hrs, seconf in 3 anfd half, thirs in 3 hrs, 4th in 3hrs…..
Becuase they kniew the steps , place of materials, sttructure and weight
(Learning curve concept, leARNING SITE CONDITIONS)
Like if i have 100 winfows the average will be 3 hrs

Question 14

Repetitive tasks are best to track productivity

Answer 14

true , as we tracked in the windows case

Question 15

If the same workers moved to a new project with different contractor and different site

Answer 15

Probaably they will start at 5 because of the site conditions

Question 16

Time is the result of knowing the quantity of work and productivity(crew)

Answer 16

true

Question 17

What if we have multiple crews, one that moves materials , other order and other install

Answer 17

I need to understand each of the taske , and i will have productivity at microlevel and at macrolevel
I will need to do simulation ( software.)

Question 18

For transportation and quieing we do simulation as that in the summer course

Answer 18

true

Question 19

To be able to get data on productivity , u need to start on data on maximum potential ideal productivity, then starts to apply factors

Answer 19

true

we make adjustment to maximum ideal potential productivity

Question 20

When have multiple crews , productivity might be dependent so u wont be able to account for it (like competing for crane

Answer 20

true

u will need to develop factors

Question 21

Productivity data best comes from previous experience

Answer 21

true, contractor with database will perform better in estimation