Construction Croductivity-WRITE SYSTEM

1. helpdesk@construction-productivity.co.uk
htt://www.construction-productivity.co.uk
ON SITE
PRODUCTIVITY-
WRITE SYSTEM

2. On-Site Construction Productivity Using
the WRITE System
 Existing construction productivity
measurement techniques are not
capable of providing the real-time
productivity data to project managers
and engineers for analyses and
sharing the data among participants
involved in construction operations.

3. On-Site Construction Productivity Using
the WRITE System
 On-site productivity problems cannot be taken
just in time.
 To address these shortfalls, the Wireless Real-
time Productivity Measurement (WRITE)
System was developed.
 it can measure the on-site construction
productivity in real time.
 In addition, an on-site construction productivity
improvement model using the WRITE System
and the benchmark data was developed.

4. WRITE System
Objective Approach-
 The real-time productivity data measured by
the WRITE System was compared to the
benchmark productivity data.
 The results of the comparison provided the
necessary information for:
 project management team to determine if
immediate actions should be taken

5. WRITE System
 Secondly, it provides an advanced
technology for managers to determine on-
site construction productivity in real time.
 Improving on-site could be taken just in time
if needed.
 These advancements enhance the
contractors’ capability of managing
construction projects.

6. WRITE System
 Productivity data have been widely used as
performance indicators:
 to evaluate construction operations throughout
the entire phase of construction.
 Construction companies must continuously
track productivity in order to measure their
performance.
1. Maintain profitability
2. Prepare future biddings

7. WRITE System
 Measuring productivity on site has been an
important task in the construction industry.
 In the past many On-site productivity
measurement techniques have been developed.
They include:
 questionnaires
 stopwatch studies
 photography
 time-lapse videos
 video-taping

8. WRITE System
 In recent years, real-time
monitoring systems have become
key methods to reduce the gap
between:
1. Actual
2. planned production rates
In an effective way.

9. On-Site Construction Productivity Using
the WRITE System
A real-time video system was
developed by Everett and
Slocum.
For monitor lifting activities of
crane in attempts to improve both
productivity and safety of crane
operations.

10. WRITE System
Since 2000,
 wireless technologies, such as:
 global positioning system (GPS)
 radio frequency identification (RFID)
system, were utilized
 Have been adopted in construction In
order to track the current status of the
resources and activities.

11. On-Site Construction Productivity Using
the WRITE System
 A GPS technology was used to
automatically measure earthmoving
performance.
 It is by identifying the locations of
equipment at regular time intervals,
 Converting the information into project
productivity (Navon and Shpatnitsky
2005).

12. WRITE System
 A web-based camera was used to
monitor interior construction operations.
 This web-based network technology
produced an opportunity to avoid using a
wired network connection.
 In a congested construction jobsite not a
good idea (Kang and Choi 2005).

13. On-Site Construction Productivity Using
the WRITE System
 Existing on-site construction productivity
measurement methods have some
common limitations.
 They are unable to provide the real-time
productivity data for analyses, and
sharing the data among participants.

14. WRITE System
DEVELOPMENT OF WRITE SYTEM
 The developed WRITE system
includes:
 A video camera;
 a digital camera;
 a data processor;

15. WRITE System
 an AC transformer;
 two antennas;
 A laptop computer as shown in Fig 1.
 The preliminary test results indicated that
the developed system can measure the
on-site construction productivity accurately
(Kim 2008)

16. WRITE System

17. Framework of the WRITE System

18. Development of the Productivity
Improvement Model
 After building the WRITE System;
 a model for the on-site construction
productivity improvement was developed.
In this model:
 the first task is to collect pictorial data in
the construction site using the WRITE
System.

19. Development of the Productivity
Improvement Model
The second task is:
 to determine the real-time productivity
data which is the ratio of working and
nonworking time.
The third task is:
 to compare the real-time productivity data
with the productivity benchmark data.

20. WRITE System
During the comparison,
 Management team MUST answer two
questions, and then make productivity
improvement decisions accordingly.
The first question
 whether the real-time productivity data is
higher than the benchmark data at which
action should be taken.

21. WRITE System
If the answer for this question is no,
 management needs to take action
immediately to improve the on-site
productivity.
If it is yes,
 management goes to the next stage to
compare the real-time data with the
acceptable benchmark data.

22. WRITE System
 If the real-time data is > than the acceptable
benchmark data,
 No action is needed.
 Otherwise, management needs to be aware that
action may be needed in the near future.
 It follows with a close monitoring at the construction
site.
 The developed model can be utilized for the entire
period of construction or for the segments of
construction.

24. WRITE System
Work Breakdown Structure (WBS)
 The work breakdown structure (WBS) has
been widely used to manage the project.
 WBS is defined as “a deliverable-oriented
grouping of project elements”.
 which organizes and defines the hierarchical
structure of the entire project (Jung and Woo
2004).

25. WRITE System
 It is often used in the complex
construction projects.
 To identify project information.
 Improve the efficiency of control
processes.

26. WRITE System
 A WBS shows the relationship of all
project activities.
 It is at important and decisive levels.
 WBS makes each activity more
manageable and measurable.
 The number of levels depends on the
size and complexity of the projects (U.S.
Department of Energy 1997).

27. On-Site Construction Productivity Using
the WRITE System
 The bridge reconstruction project used in
the field experiments was broken down
into four levels. They are:
 including Level 1 (project)
 Level 2 (work zone)
 Level 3 (activity)
 and Level 4 (operation)
 Examples of the levels of steel girder
bridge WBSs are shown in Table 1.

28.  Table 1. WBS for steel girder bridge reconstruction
 Level 1 (Project) Level 2 (Work Zone) Level 3 (Activity) Level 4
(Operation)
 Steel Girder Bridge General Mobilization Set up Crane
 Abutment Traffic Control Moving concrete safety barrier
 Pier 1 Demolition Driving pile
 Pier 2 Excavation Forming
 Pier 3 Abutment 1 Structural excavation
 North side Abutment 2 Slope protection (filter fabric and rock)
 South side Pier Drill Shafts Set bearing devices
 Span 1 Pier Columns Unload beams
 Span 2 Pier Cap Set beams
 Span 3 Slope protection Install diaphragms
 Span 4 Beam Setting Bolting and tightening splice
 Deck Forming Ground splice
 Reinforcing Deck Prepare deck material
 Bridge Barrier Rail Prepare deck forming
 Concrete Barrier Overhangs
 Backfill Abutments Strip
 Approach road Place backwall (strip drain & backfill)
 Tying rebar
 Pouring and curing
 Others
 Strip and check elevation

29. WRITE System
Determining Productivity Benchmark Data
 Benchmarking has been used as a tool to
improve productivity since the early 1980s.
 The Construction Industry Institute (CII) has
established construction productivity metrics
and a reporting format for construction
productivity benchmarking and improvement
(Han et al. 2005).

30. WRITE System
Actual working time of construction
workers is at 56% in nuclear plant
construction projects (Hewage and
Ruwanpura 2006).
Christian and Hachey (1995)
studied concrete-placement
operations. Their finding showed
that:

31. WRITE System
There are 61% working time and
39% nonworking time.
According to the previous
research projects, the ratio of
working time and nonworking time
ranges approximately from 50:50
to 60:40.

32. WRITE System
 There is no consensus on the
acceptance ratio of working time verse
nonworking time in the construction
industry.
 because construction projects have
different natures such as different
types of projects, activities, and
operations.

33. WRITE System
Productive and non-productive
time for five bridge operations
were identified as:
deck forming
tying rebar
installing finisher

34. WRITE System
 backfilling
 and placing approach road footing.
 A total of 66 hours of video tapes were
recorded using the WRITE System to
determine the productivity rates for the
five bridge operations.

35. On-Site Construction Productivity Using
the WRITE System
 These videos were all taken zoomed-in to
clearly identify:
 the productive time;
 nonworking;
 time for each operation.
 The ratio of productive and non-productive
time was: 86% and 14% on average as
shown in Table 2.

36. WRITE System
 Table 2. Ratio of working and nonworking time determined by
the WRITE System
 Operation Time (Second) Percentage (%)
 Time Nonworking(nonproductive)
 Time Working
 Time Nonworking
 Time
 Deck forming 24,720 2,160 92 8
 Tying rebar 40,320 5,880 87 13
 Installing finisher 71,230 21,100 77 23
 Placing backwall, strip drain, and backfill 44,850 1,950 96
4
 Grade and tie approach road footing 21,275 2,725 89 11
 Total 202,395 33,815 86 14

37. WRITE System
 The benchmark data were based on
professional intuitions about rates of
working time and nonworking time for
each of the five bridge construction
operations.

38. WRITE System
 Table 3. List of survey construction
professionals
 Name Company Construction Specialty
Position
 Ken Johnson BRB contractors, Inc. Bridge
Project Manager
 Mike Laird BRB contractors, Inc. Bridge and
Plant Project Manager
 Ray Rinne A.M. Cohron & Son, Inc.
 Bridge Superintendent
 Christopher J. Rech A.M. Cohron & Son, Inc.
Bridge Project Manager

39. WRITE System
 Table 4 shows acceptable ratios provided
by four survey participants.
 The overall average ratio for working time
(WT) was 81%
 and overall average ratio for nonworking
time (NWT) was 19%.
 Tying rebar had the highest nonworking
ratio of 21%,
 while deck forming had the lowest rate of
16%. T

40. On-Site Construction Productivity Using
the WRITE System
 According to the survey participants, they
can accept the working time ratio of at least
79% for these bridge operations.
 Table 5 presents ratios at which action
should be taken by project managers to
improve on-site construction productivity.

41. WRITE System
 The overall average ratio for WT was
75%
 and overall average for NWT was
25%.
 Tying rebar had the highest
nonworking time rate of 28%,
 while deck forming had the least
nonworking time rate of 23%.

42.  Table 4. Acceptable ratio
 Operation BRB 1 BRB 2 A.M. Cohron 1 A.M. Cohron 2 Average
 WT
 (%) NWT
 (%) WT
 (%) NWT
 (%) WT
 (%) NWT
 (%) WT
 (%) NWT
 (%) WT
 (%) NWT
 (%)
 Deck forming 85 15 80 20 85 15 85 15
84 16
 Tying rebar 80 20 75 25 80 20 80 20
79 21
 Installing finisher 85 15 75 25 85 15 85 15
82 18
 Placing backwall, strip drain, and backfill 70 30 80 20 85 15
85 15 80 20
 Grade and tie approach road footing 80 20 80 20 85 15
85 15 82 18
 Average 80 20 78 22 84 16 84 16
81 19
 Note: WT–Working Time; NWT–Nonworking Time

43. WRITE System
 Table 5. Ratio at which action should be taken
 Operation BRB 1 BRB 2 A.M. Cohron 1 A.M. Cohron 2 Average
 WT
 (%) NWT
 (%) WT
 (%) NWT
 (%) WT
 (%) NWT
 (%) WT
 (%) NWT
 (%) WT
 (%) NWT (%)
 Deck Forming 75 25 75 25 80 20 80
20 77 23
 Tying rebar 70 30 70 30 75 25 75
25 72 28
 Installing finisher 75 25 70 30 80 20 80
20 76 24
 Placing backwall, strip drain, and backfill 60 40 75 25 80
20 80 20 74 26
 Grade and tie approach road footing 70 30 75 25 80
20 80 20 76 24
 Average 70 30 73 27 79 21 79
21 75 25
 Note: WT–Working Time; NWT–Nonworking Time

44. WRITE System
 Table 6 presents the results of the comparison
between the benchmarking data from the survey
and the real-time productivity data determined by
the WRITE System.
 For the operation of installing finisher,
 the nonworking ratio of 24% was equal to the
ratio at which action should be initiated by the
construction manager.
 The rest of operations had larger working time
ratios than the minimum required working ratios.

45.  Table 6. Data comparison between the WRITE System and the benchmarks
 Operation Acceptable
 Ratio Ratio at which action should be taken WRITE
 System
 WT
 (%) NWT
 (%) WT
 (%) NWT
 (%) WT
 (%) NWT
 (%)
 Deck Forming 84 16 77 23 92 8
 Tying rebar 79 21 72 28 87 13
 Installing finisher 82 18 76 24 76 24
 Placing backwall, strip drain, and backfill 80 20 74 26 96
4
 Grade and tie approach road footing 82 18 76 24 89
11
 Average 81 19 75 25 88 12
 Note: WT – Working Time; NWT – Nonworking Time

46. WRITE System
 By comparing the rates from the WRITE System
to the benchmark data, project managers can
take actions for improving on-site construction
productivity in real time.
 As shown in Table 7, there are three cases that
project managers can make decision using the
developed model.
 First, if the productivity ratio measured by the
WRITE System is higher than the acceptable
ratio,
 then, no action is required.

47. WRITE System
 Second, if the ratio is between acceptable
ratios and ratios,
 at which action should be initiated,
 then, management needs to be aware that
an action may be needed in the near
future.
 Finally, if the ratios are lower than the
minimum required rate,
 then, the project manager needs to take
actions immediately.

48. WRITE System
 Table 7. Making management decisions using
the WRITE System
 No. Ratios from the WRITE System
Action
 1 Higher than acceptable ratios No action
needed
 2 Between acceptable ratios and ratios at which
action should be taken Aware that action may
be needed
 3 Lower than ratios at which action should be
taken Action is required