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8/10/2019 Parts 1 & 2 Resource Management Presentation
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Dr. HeshamDr. Hesham ElbakryElbakry
Ph.D. Construction Projects ManagementPh.D. Construction Projects ManagementConsultant in Construction Projects ManagementConsultant in Construction Projects Management
ByBy
Project Resources ManagementProject Resources Management
Cairo UniversityCairo University Faculty of EngineeringFaculty of Engineering
Civil Engineering DepartmentCivil Engineering Department
2Dr. Hesham Elbakry
Content1. Introduction
2. Resource Management
2.4 Resource leveling (Smoothing)/Scheduling
2.2 Resource Allocation/Loading
2.3 Resource Aggregation
2.1 Resource Definition
2.5 LOB as a Resource Oriented Scheduling Technique
2.4.1 Method of Moment for Resource Leveling
2.4.2 Heuristic Procedure for Resource Leveling2.4.3 Leveling Combined Resources
2.4.4 Scheduling Limited Resources
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3Dr. Hesham Elbakry
Content (Continue)
3. Cash Flow Management
4. Management of Construction Personnel
5. Material Management
6. Equipment Management
7. Sub-Contractor Management
1. Introduction1. Introduction
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5Dr. Hesham Elbakry
ActivitiesActivitiesRelationshipsRelationships
DurationsDurations
Analysis ofAnalysis of
SchedulingScheduling
by CPMby CPM
6Dr. Hesham Elbakry
CPM AlgorithmCPM Algorithm
ButBut
Impractical Schedule
Management of available resources is requiredManagement of available resources is required
Duration-driven
analysis
Assumption of
resources availability
Not all required
resources are available
ThusThus
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7Dr. Hesham Elbakry
2.1 Resource Definition
Things needed to have the work done
Consumable Non-Consumable
Key Res.(Expensive,
not available)
(Skilled Labour,Special Equip.)
Secondary Res.(Available)
(Normal labouror Equip.)
General Res.(Used by most
of the
Activities)(Site Facilities)
Apply Resource Management
8Dr. Hesham Elbakry
etcetc
SpaceSpace
SubContractors
SubSub
ContractorsContractorsCashCashCash
EquipmentEquipmentEquipment
LabourLabourLabour
MaterialMaterialMaterial
ResourcesResourcesResources
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9Dr. Hesham Elbakry
2.2 Resource Allocation/Loading
Assigning the resources (with its no.) that
required to execute each activity
More than one type of resources may be
assigned to a specific activity
10Dr. Hesham Elbakry
2.3 Resource Aggregation
Summation of allocated resources
used by all activities onperiod-by-period basis
Individual aggregation of each type
of used resources
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11Dr. Hesham Elbakry
8
777777151515151515151588131355Total Res.Total Res.
requirerequire
CC
BB
22
AA
10109988776655443311weekweek
ActivityActivity5 5
8 8 8 88
7777 7 7 7
Resource Aggregation/Chart
ResourceResourceAggregationAggregation
ChartChart 5
10
15
12Dr. Hesham Elbakry
Resource Aggregation Chart (ES&LS&CP)
ResourceU
nits
Week
1
23
4
5
6
7
8
1 2 3 4 5 6 7 8 9 10 11
Resource Aggregation/Earliest Starts
Resource Aggregation/Latest StartsResource Aggregation of Critical Path Activities
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13Dr. Hesham Elbakry
2.4 Resource Leveling/Scheduling
Time
ConstrainedResource
Constrained
Time & Resource Constrained Projects
Resource scheduling is applied to
prioritize and allocate the use
of the available constrained
no. of resources
ResourceManagement
Resource leveling is applied to
smooth resource fluctuation
along with the constrained
project duration
14Dr. Hesham Elbakry
Project
Resource/Time
Relationship
Resource Resource
T
Time
Resource
T
Resource
LimitR
Time Constrained Project
T1= TT1
R1
R1
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15Dr. Hesham Elbakry
2.4.1 Method of Moment for Res. Leveling
Minimum Moment Algorithm
As a heuristic approach to calculatea measure of the fluctuation in
daily resource demand
Evaluate resource histograms alternatives
16Dr. Hesham Elbakry
1
Days
ResourceAmount
1 2 3 4 5 6 7 8 9 10 11 12
23
4
5
6
Histogram 2
Histogram 1
Histogram 1 : Mx = 83
Histogram 2 : Mx = 80
Mx = j =1
n
[(1 Resource Demandj )Resource demandj/2]
Mx =
j =1
n
12
(Resource Demandj )2
Where: n = working-day number of project finish date
Mx2 < Mx1
Thus
Hisogram 2 is better
than histogram 1
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17Dr. Hesham Elbakry
To select whichactivity/ies
To select whichTo select whichactivity/activity/iesies
To enhanceRes. fluctuation
To enhanceTo enhanceRes. fluctuationRes. fluctuation
To be movedforward
To be movedTo be movedforwardforward
Throughits floats
ThroughThroughits floatsits floats
MethodologyMethodology
2.4.2 Heuristic Procedure for Res. Leveling
18Dr. Hesham Elbakry
Example 2.1
Assuming that one resource type will be used
during the contract,
The activities involved in the construction of a
certain project are given in the following table,
Determine the minimum level of this resource
required to complete the project?
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19Dr. Hesham Elbakry
00J, K, L, MJ, K, L, M22NN44B, H, IB, H, I22MM22B, HB, H33LL22F, GF, G77KK44E, FE, F22JJ00DD44II11DD66HH33CC66GG22BB66FF11BB22EE22AA33DD22AA55CC00AA22BB 00-- --00AA
ResourceResource
(units/week)(units/week)PredecessorsPredecessorsDurationDurationActivityActivity
20Dr. Hesham Elbakry
Solution / Steps
002018N77119M 66129L
001811K88108J9273I6093H00115G3082F12442E6030D0050C3020B0
TF
000A
FFEFESID
1. Prepare a complete activity schedule
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21Dr. Hesham Elbakry
M
L
J
I
H
F
E
D
B
N
K
G
C
2019181716151413121110987654321
2. Draw the project
bar chart
based upon ES
Show critical
activities first
22Dr. Hesham Elbakry
M, 4
L, 2
J, 4
I, 0
H, 1
F, 2
E, 1
D, 2
B, 0
N, 0
K, 2
G, 3
C,2
2019181716151413121110987654321
3. Allocate Resource
4. Aggregate Resource
002222224913866656744
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23Dr. Hesham Elbakry
M, 4
L, 2
J, 4
I, 0
H, 1
F, 2
E, 1D, 2
B, 0
N, 0K, 2
G, 3C,2
2019181716151413121110987654321
002222224913866656744
Total Res. Usage= Unit Period Usage = 90 Unit
= 90/18 = 5 Res. Units/period
Average Res. Usage=Total Res. Usage/Utilized period
5. Get Total Res. Usage&Average Res. Usage
24Dr. Hesham Elbakry
002222224913866656744
M, 4
L, 2
J, 4
I, 0
H, 1
F, 2
E, 1
D, 2
B, 0
N, 0
K, 2
G, 3
C,2
2019181716151413121110987654321
6. Assign TF (dashed
line beside lower side)
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25Dr. Hesham Elbakry
002222224913866656744
M, 4
L, 2
J, 4
I, 0
H, 1
F, 2
E, 1
D, 2
B, 0
N, 0
K, 2
G, 3
C,2
2019181716151413121110987654321
7. Assign FF (dashed
line beside upper side)
26Dr. Hesham Elbakry
Time
2019181716151413121110987654321
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Units
8. Resource usage
histogram
could be obtained
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27Dr. Hesham Elbakry
002222224913866656744
M, 4
L, 2
J, 4
I, 0
H, 1
F, 2
E, 1
D, 2
B, 0
N, 0
K, 2G, 3
C,22019181716151413121110987654321
ime2019181716151413121110987654321
123456789
1011121314
Units
Average Res. usage =5 units/period
9. Define maxRes. demand
28Dr. Hesham Elbakry
002222224913866656744
M, 4
L, 2
J, 4
I, 0
H, 1
F, 2
E, 1
D, 2
B, 0
N, 0
K, 2
G, 3
C,2
2019181716151413121110987654321
10. Prioritize moving
activities (Consideringless successors & no. ofRes. usage & max FF & TF)
Move M (7 weeks)
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29Dr. Hesham Elbakry
002222224913866656744
M, 4
L, 2
J, 4
I, 0
H, 1
F, 2
E, 1
D, 2
B, 0
N, 0
K, 2
G, 3
C,2
2019181716151413121110987654321
00662222459866656744
00+ 4+ 422224- 4- 4866656744
11. Re-aggregate
Res. usage
30Dr. Hesham Elbakry
Same FF
Moved (7 weeks)
New ES = 16
16 18
Same FF
12. Revise
FF & TF
New FF = 9
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31Dr. Hesham Elbakry
00662222459866656744
M, 4
L, 2
J, 4
I, 0
H, 1
F, 2
E, 1
D, 2
B, 0
N, 0
K, 2
G, 3
C,2
2019181716151413121110987654321
Move J (6 weeks)
13. Repeat step
no. 10
Thus
32Dr. Hesham Elbakry
14. Repeat steps
no. 11 & 12
00662222459866656744
M, 4
L, 2
J, 4
I, 0
H, 1
F, 2
E, 1
D, 2
B, 0
N, 0
K, 2
G, 3
C,2
2019181716151413121110987654321
00666622455466656744
+ 4+ 4- 4- 4
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33Dr. Hesham Elbakry
00666622455466656744
M, 4
L, 2
J, 4
I, 0
H, 1
F, 2
E, 1
D, 2
B, 0
N, 0
K, 2
G, 3
C,2
2019181716151413121110987654321
Move L (2 weeks)
15. Repeat step
no. 10
Thus
34Dr. Hesham Elbakry
00666622455466656744
M, 4
L, 2
J, 4
I, 0
H, 1
F, 2
E, 1
D, 2
B, 0
N, 0
K, 2
G, 3
C,2
2019181716151413121110987654321
00666644433466656744
+ 2+ 2- 2- 2
16. Repeat steps
no. 11 & 12
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35Dr. Hesham Elbakry
00666644433466656744
M, 4
L, 2
J, 4
I, 0
H, 1
F, 2
E, 1
D, 2
B, 0
N, 0
K, 2
G, 3
C,2
2019181716151413121110987654321
Move E (10 weeks)
17. Repeat steps
no. 9 & 10
Thus
36Dr. Hesham Elbakry
00666644433466656744
M, 4
L, 2
J, 4
I, 0
H, 1
F, 2
E, 1
D, 2
B, 0
N, 0
K, 2
G, 3
C,2
2019181716151413121110987654321
00666655433466655644
+ 1+ 1- 1- 1
18. Repeat
steps
no. 11 & 12
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37Dr. Hesham Elbakry
00666655433466655644
M, 4
L, 2
J, 4
I, 0
H, 1
F, 2
E, 1
D, 2
B, 0
N, 0
K, 2
G, 3
C,2
2019181716151413121110987654321
Move H (2 weeks)
19. Repeat steps
no. 9 & 10
Thus
38Dr. Hesham Elbakry
00666655433466655644
M, 4
L, 2
J, 4
I, 0
H, 1
F, 2
E, 1
D, 2
B, 0
N, 0
K, 2
G, 3
C,2
2019181716151413121110987654321
00666655444466644644
+ 1+ 1- 1- 1
20. Repeat
stepsno. 11 & 12
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39Dr. Hesham Elbakry
00666655444466644644
M, 4
L, 2
J, 4
I, 0
H, 1
F, 2
E, 1
D, 2
B, 0
N, 0
K, 2
G, 3
C,2
2019181716151413121110987654321
Move F (1 weeks)
21. Repeat stepsno. 9 & 10
Thus
40Dr. Hesham Elbakry
00666655444466644644
M, 4
L, 2
J, 4
I, 0
H, 1
F, 2
E, 1
D, 2
B, 0
N, 0
K, 2
G, 3
C,2
2019181716151413121110987654321
00666655444666644444
+ 2- 2
22. Repeat
stepsno. 11 & 12
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41Dr. Hesham Elbakry
00666655444666644444
M, 4
L, 2
J, 4
I, 0
H, 1
F, 2
E, 1
D, 2
B, 0
N, 0
K, 2
G, 3
C,2
2019181716151413121110987654321
Final Resource Usage / Periods
42Dr. Hesham Elbakry
00666655444666644444
M, 4
L, 2
J, 4
I, 0
H, 1
F, 2
E, 1E, 1
D, 2
B, 0
N, 0K, 2
G, 3C,2
2019181716151413121110987654321
Time2019181716151413121110987654321
1234567891011121314Units
Average Res. usage =
5 units/period
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43Dr. Hesham Elbakry
2.4.3 Leveling Combined Resources
Smooth combinationof Resources
Smooth eachResource individually
Optimum Resource
leveling couldbe expected only forlast smoothed Res.
Approximate leveling
could be achievedfor all Resources(more effective)
44Dr. Hesham Elbakry
Example 2.2
Consider Example 2.1,
Assuming that the activities involved in that projectare using another resource R2 in addition to the
originally introduced resource R1.
Smooth the demand of resources
R1 and R2 simultaneously.
If the usage of R2 is as in the following table,
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45Dr. Hesham Elbakry
000022NN334422MM882233LL002277KK554422JJ550044II001166HH223366GG552266FF441122EE002233DD332255CC220022BB 000000AA
Resource RResource R22
(units/week)(units/week)
Resource RResource R11
(units/week)(units/week)
DurationDuration
(week)(week)ActivityActivity
46Dr. Hesham Elbakry
Solution / Steps
73344M 108822L
20022K95544J55500I10011H52233G75522F54411E20022D 53322C
22200B
ERUR2R1ID
Step no. 1
Construct table of demand ofEquivalent Resource Usage
(ERU) of the two resources
together (by adding the
resource rates of the two
Resources simultaneously).
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47Dr. Hesham Elbakry
M
L
J
I
H
F
E
D
B
NK
G
C2019181716151413121110987654321
3. Draw the project
bar chart
based upon ES
Show criticalactivities first
2. Prepare a complete activity schedule
48Dr. Hesham Elbakry
M, 4
L, 2
J, 4
I, 0
H, 1
F, 2
E, 1
D, 2
B, 0
N, 0
K, 2
G, 3
C,2
2019181716151413121110987654321
4. Allocate Resource R1
5. Aggregate Resource R1
002222224913866656744
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49Dr. Hesham Elbakry
M, 3
L, 8
J, 5
I, 5
H, 0
F, 5
E, 4
D, 0
B, 2
N, 0
K, 0
G, 2
C,3
2019181716151413121110987654321
6. Allocate Resource R2
7. Aggregate Resource R2
000000008131877121213171255
50Dr. Hesham Elbakry
Step no. 8
Construct table of Equivalent Resource Usage
(ERU) of the two resources by adding the
histograms of R1 & R2 together.
4 00222222491386665674R1
5 00000000813187712121317125R2
9 00222222122231151318181823199ERU
+
=
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51Dr. Hesham Elbakry
Step no. 9
- Considering activities demand & Histogram0f ERU,
- Use same methodology applied for smoothing
single resource (example 2.1) to smooth ERU.
The ERU demand & Histogram will be smoothedas follows
52Dr. Hesham Elbakry
002222221222311513181818231999
M, 7
L, 10
J, 9
I, 5
H, 1
F, 7
E, 5
D, 2
B, 2
N, 0
K, 2
G, 5
C, 5
2019181716151413121110987654321
Same procedure as
applied for single resource
ERU Histogram
ERU Demand
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53Dr. Hesham Elbakry
0012121211119912131313181811151299
M, 7M, 7
L, 10L, 10
J, 9J, 9
I, 5
H, 1
F, 7F, 7
E, 5
D, 2
B, 2
N, 0
K, 2
G, 5
C, 5
2019181716151413121110987654321
Get schedule timing of
final smoothing of ERU
54Dr. Hesham Elbakry
00444666656666633544
M, 4M, 4
L, 2L, 2
J, 4J, 4
I, o
H, 1
F, 2F, 2
E, 1
D, 2
B, 0
N, 0
K, 2
G,3
C, 2
2019181716151413121110987654321
10. Use final scheduling to
get R1 Smoothed Histogram
R1 Smoothed Histogram
R1 Demand
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55Dr. Hesham Elbakry
888553377771212812755
M, 3M, 3
L, 8L, 8
J, 5J, 5
I, 5
H, 0
F, 5F, 5
E, 4
D, 0
B, 2
N, 0
K, 0
G, 2
C, 3
2019181716151413121110987654321
11. Use final scheduling to
get R2 Smoothed Histogram
R2 Smoothed Histogram
R2 Demand
56Dr. Hesham Elbakry
PrioritizeactivitiesPrioritizePrioritizeactivitiesactivities
To match
Res. LimitationTo matchTo matchRes. LimitationRes. Limitation
Through
selected rulesThroughThrough
selected rulesselected rules
To be moved
forwardTo be movedTo be moved
forwardforward
MethodologyMethodology
2.4.4 Scheduling Limited Resources
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57Dr. Hesham Elbakry
Requirerecalculation of
network scheduling
Examples
-Earliest Start Time (EST)
-Least Total Float (LTF)
Examples
- Current Float Technique
- Earliest Late Start (ELS)
Methods of Scheduling Limited Resources
Don t requirerecalculation of
network scheduling
Will be introduced
58Dr. Hesham Elbakry
Procedure of Resource Scheduling Using ELS
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59Dr. Hesham Elbakry
Example 2.3
The following table illustrate the activities
of a Project, as well as its resources usage
Schedule the project so that:
the daily resource usage matching resourcesLimits & minimum project duration extension.
If the resources limits are as introduced by the table
60Dr. Hesham Elbakry
00
11
0011
11
11
00
00
11
11
00
33
66
4400
44
00
44
22
44
55
22
--
--
--AA
DD
BB
BB
FF
E, HE, H
CC
G, JG, J
44
66
2288
44
1010
1616
88
66
66
1010
AA
BB
CCDD
EE
FF
GG
HH
II
JJ
KK
RR22 11RR11 88
Resource (Units/week)Resource (Units/week)PredecessorPredecessorDurationDuration
(Week)(Week)ActivityActivity
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61Dr. Hesham Elbakry
Solution StepsApply Procedure of ELS Method
62Dr. Hesham Elbakry
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63Dr. Hesham Elbakry
Flow Chart of General Resources Management
64Dr. Hesham Elbakry
2.5 Line Of Balance (LOB)
as a Resource Oriented Scheduling Technique
Technique for
Resource Oriented Scheduling of
Repetitive/Linear projects;
(a) Projects involving several uniform units of work(such as multiple houses or typical floors in abuilding) or
(b) Being geometrically linear (such as highway,
pipeline, and utility projects).
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65Dr. Hesham Elbakry
The Objectives/Benefits of the LOB Technique
To determine a balanced mix of resources andsynchronize their work so that they are fullyemployed and non-interrupted.
Interesting representation of the schedule, givenlarge amount of data for the repetitive units.
Scheduling the activities so that a projectdeadline is met using predefined resourceavailability limits.
66Dr. Hesham Elbakry
LOB Basic Representation
Graphical Representation of the Activities of
the Repetitive Unites of a Project
Consider a high-rise building of 10 typical floors.
Assuming that the construction of each typical floorinvolves 4 inter-related sequential activities; (A, B, C, D).
The Project LOB Representation may be as follows:
Example
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67Dr. Hesham Elbakry
12
3
4
5
67
8
9
10
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
The graphical representation of LOBwill be as follows
RepetitiveUnits
1- The vertical axis represents the repetitive unites (floors)
4- Each bar width represent the duration of the activity forone unit of the project repetitive unites (DA, DB,.)
DA DB DADC
DA CB
3- Each sloping bar represent one of the units activities
Time
2- The Horizontal axis represents the time (days, weeks )
68Dr. Hesham Elbakry
12
3
4
5
6
7
8
9
10
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
RepetitiveUnits
DA DB DADC
DA CB
Time
5- A horizontal line at any unit intersects with theactivity bars at the planned start and finish timesof the work in that unit.
Start
4Start
11
End
22
End
16
6- A vertical line at any date (time) shows the plannedwork that should be completed/started before and
on that date.
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69Dr. Hesham Elbakry
RepetitiveUnits
12
3
4
56
7
8
9
10
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
Time
DA CB
DA DB DADC
Project End Date
8- The finish time of the last unit in the last activityrepresents the end date of the project.
7- The slope of each activity represents its plannedrate of progress and this is direct function of thenumber of crews involved in the activity
ActivityProgress
Rate
70Dr. Hesham Elbakry
More information could be added/extracted as follows
9- The number of crews employed in each taskcould be graphically represented (by a differentpattern for each crew). Thus,
DA CB
12
3
4
5
6
7
8
9
10
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
RepetitiveUnits
DA DB DADC Time
The synchronized movement of the crews fromone unit to the other could be easley checked.
Crew 1
Crew 2
Crew 3
Crew 1
Crew 2
Crew 3
Crew 1
Crew 2
Crew 3
Crew 1
Crew 1 works in unites1,4,7,10 and leaves site on day 12
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71Dr. Hesham Elbakry
10- A buffer time could be introduced (as a float time) toprevent interference between the sequential activities incase an activity is slightly delayed
DA CB
12
3
45
6
7
8
9
10
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
Repeti
tiveUnits
DA DB DC Time
Crew 1
Crew 2
Crew 3
Crew 1Crew 2
Crew 3
Crew 1
Crew 2
Crew 3
Crew 1Buffer time one day between A & B
Buffer time one day between C & D
When a slower activity is to follow a faster activity (e.g., D
follows C), a buffer time is to be added to the startof first unit of Activity C,When a faster activity is to follow a slower activity (e.g., B
follows A), a buffer time is to be added at the end offinal unit of Activity A
72Dr. Hesham Elbakry
11- Activities production rates
Speeding one activity so that conflict point changesfrom bottom to top increases project duration,
A good scheduling strategy is to schedule the activitiesas parallel as possible to a desired project delivery.
Changing the production rate (slope) of any activitymay changes the project duration,
Effect of accelerating production rate
are indicated by the following diagrams
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73Dr. Hesham Elbakry
Project End at T1 = 27 day
TimeRepetitiveUnits
12
3
4
56
7
8
9
10
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
DA CB
Rate 1
Activity
B
Rate 1
Project End at T2 = 30 day
T2 > T1
RepetitiveUnits
12
34
5
6
7
8
9
10
1 21
Time
A
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 22 23 24 25 26 27 28 29 30 31 32 33 34 35
Activity
B
Rate 2
Rate 1 > Rate 2
Rate 2
B C D
74Dr. Hesham Elbakry
LOB Calculations
The LOB formulation involves four main issues as follows:
- Crew synchronization and work continuity equation;
- Computation of a project delivery rate that meets a givendeadline duration;
- Calculating resource needs for critical and non-criticalactivities; and
- Drawing the LOB schedule.
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75Dr. Hesham Elbakry
Crew Synchronization
C = no. of crews
D = Activity Duration
R = Activityproduction rate
Then : R = C/D . . . . . . . . . . . . . . . . (1)For the given case: R = 3/3 = 1 unit/day
To accelerate the production rate, Use 4 crews
Then: Rnew= 4/3 = 1.33 units/day
1
2
3
4
Crew 1
Crew 3
Crew 2
RUnits
D Time
76Dr. Hesham Elbakry
1
2
3
4
Crew 1
Crew 3
Crew 2
RU
nits
Time
R = C/D
-Work continuity is achieved by shifting the start ofeach unit from its previous one by a time D/C or 1/R.
D/C D/C D/C
Start times shift
D/C
- Shifting the crew starts enhance the demand of thiscrews to other resources.
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77Dr. Hesham Elbakry
Meeting The Project Deadline Duration
-A basic objective in CPM-LOB calculation isto meet a given deadline for finishing (n)
repetitive unites.
- By LOB, it is possible to formulate a strategyfor meeting a dead line by calculating the
desired rate of delivery (Rd) for the units as
follows:
78Dr. Hesham Elbakry
Rd1
2
n
Units
Time
.
T1
T1= CPM Duration of Unit 1
TL
TL= Project Deadline Duration
-The delivery rate (Rd) is the minimum raterequired to meet the project desired deadline
Rd= (n-1)/(TLT1) . . . . . . . . . (2)
-Any higher rate result in shorter project durationbut also more crew use/cost.
Notes
n-1
Project
Deadline
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79Dr. Hesham Elbakry
Calculating Resources Needing
-To match the project desired deadline, thecalculated rate of delivery [Rd= (n-1)/(TLT1)]
should be applied to all critical activities.
- On the other hand, for non-critical activities, thetotal float should be used to slow the rates of
such activities. Then Rdwill be as follows:
ExampleThe following network is for activities A,B,C and D
to be executed for (n) repetitive units.
80Dr. Hesham Elbakry
12345
n
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
Repetitive
Units
Time
(TL ) Project
Deadline
T1
A C
B
Rd
TLT1TLT1TFD
D
(TLT1) +TFD
RD
Ri
= (n-1)/[(TL
T1
) +TFi
]. . . . . . . . . (3)
Thus
Where (i) is the non critical activity
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81Dr. Hesham Elbakry
Applying equation (1): R=C/D
Then: Ri = Ci/Di
The no. of crews Ci Should be rounded to be Cai
Then: Rai = Cai/Di . . . . . . . . . . . . . . (4)
Equations 3 & 4 are the basis of LOB calculations
Ri= (n-1)/[(TLT1) +TFi]. . . . . . . . . (3)
82Dr. Hesham Elbakry
Example 2.4
The following table illustrates the activities involved
in the construction of 1 Km of a pipeline together
with their estimated durations,
- Calculate the number of crews needed for eachactivity, assume 1 day buffer time between activities
- Draw the LOB schedule.
The project consists of 10 similar kilometers and is
targeted to be finished in 40 days.
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--
AA
AA
B, CB, C
DD
EE
PrecedingPrecedingactivitiesactivities
11
33
11
44
11
22
Locate and clearLocate and clear
ExcavateExcavate
String pipeString pipe
Lay pipeLay pipe
Pressure testPressure test
BackfillBackfill
AA
BB
CC
DD
EE
FF
DurationDuration(days)(days)
ActivityActivitynamename
ActivityActivityno.no.
84Dr. Hesham Elbakry
Solution
1. Create CPM calculations for a single unit,Identify the following:- Total time of one unit (T1)
- ES of Critical Activities- ES & TF of non critical activities.
Buffer times 1 day
as required
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85Dr. Hesham Elbakry
- From CPM get ActivitiesTF, then get the
desired rate for all activities as follows:
2. LOB Calculations :
- Project deadline (TL) = 40 day
- Unit time (T1) = 15 day (by CPM)
Ri= (n-1)/[(TLT1) + TFi] = 9/[25 + TFi]
- Get the corresponding required no. of crews Ci
for all activities ( Ci = Ri Di )- Round up Ci : then, use the actual no. of crews
Cai to get the activities actual rates Rai = Cai/Di
86Dr. Hesham Elbakry
00
00
22
00
00
00
11
33
11
44
11
22
AA
BB
CC
DD
EE
FF
TotalTotalFloatFloat
((TFTFii
))
DurationDuration
(day)(day)ActivityActivity
(i)(i)
0.3600.360
0.3600.360
0.3330.333
0.3600.360
0.3600.360
0.3600.360
Ri =
9/[25+TFi]
0.3600.360
1.0801.080
0.3330.333
1.4401.440
0.3600.360
0.7200.720
Ci =
Ri Di
11
22
11
22
11
11
Cai =
Round of Ci
11
0.6670.667
11
0.50.5
11
0.50.5
Rai =
Cai/Di
From CPM From LOB Calculations
Use Rai and the CPM data to drew the ProjectLOB schedule as follows:
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87Dr. Hesham Elbakry
A
CB D
11
0.6670.66711
0.50.511
0.50.5
Rai
00
0022000000
11
3311441122
AA
BBCCDDEEFF
((TFTFii))DDii(i)(i)
RepetitiveUnits
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
Time
1234
5
10
6789
36 37 38 4239 40 41
EF
9 10 11 12 15.5 18.5 24 28 29 30 40 42
88Dr. Hesham Elbakry
LOB as a planning & Scheduling tool is not limited
to repetitive projects with typical units only. It is also
valid for other cases not limited to the following:
Notes:
2 - Interrupting the crewswork continuity.
3 - Execution of some activitywork starting not
from the first unit
4 - Applying variable delivery rates for any activity
1 - Existence of some non-typical units.
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89Dr. Hesham Elbakry
RepetitiveUn
its
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
Time
12345
10
6789
36 37 38 4239 40 41
Consider LOB calculations in such cases neglectingun-uniformity then adjust the graphical representation.
1 2 3 4
To Be ContinueFor further
Resource Management