conseptual estimate

2. Definitive
Estimation
Design/Engineering
Stage
Conceptual
Estimation
Detailed
Estimation
Conceptual
Stage
Execution
Phase
Project
Budget
Fair Cost
Estimation
Cost
Planning
Basic
for
Cost
Control
Feedback

3. Estimate
Class
Project Definition
(% of complete
definition)
End Usage (typical
purpose of estimate)
Methodology (typical
estimating method)
Accuracy Range (%
of variation in low
and high ranges) [a]
Preparation Effor
(index relative to
project cost)[b]
Class 5 0 -2 Concept screening Capacity factored, parametric
models, judgment or analogy
L: -20 to -50H: 30 to
100
1
Class 4 1-15 Study or feasibility Equipment factor and
parametric model
L:-15 to -30H: 20 to
50
2 to 4
Class 3 10-40 Budget authorization or
cost control
Semi-detailed unit cost with
assembly level line items
L:-10 to -20H: 10 to
30
3 to 10
Class 2 30-70 Control of bid or tender Detailed unit cost with forced
detailed take off
L:-5 to -15H: 5 t0 20 4 to 20
Class 1 50-100 Check estimate, bid or
tender
Detailed unit cost with
detailed take off
L:-3 to -10H: 3 to 15 5 to 100

4. The preparation of the first estimate, CCE would be
based on a variety of techniques, for example, historic
data or approximate quantities. When the client has
accepted the first estimate and instructs that the project
proceed to the next stage, then this becomes the first
cost plan against which further design developments
and changes are monitored.

5. During the process of design development the main duties of
the QS as part of the cost management team are as follows:
a) To check and report the cost of design solutions as they
are established or refined by the engineers
b) To prepare comparative estimates of various design
solutions or alternatives and advise the engineer
accordingly
c) As changes are introduced into the project, to estimate the
cost effect of the change and to report

6. Cost
Estimation
Project
Information
Current
Data
Data
Estimating
Methodology
Historical
Data
Cost
Estimator
Output

7. a) Project Information: the information about the current project,
including project scope and major building characteristics (such as
type and use)
b) Historical Data: the cost data for historical project and their building
characteristics
c) Current Data: the unit cost and rate (for material, labor, and
equipment), historical cost indices, and other items
d) Estimating Methodology: the method used for estimation, including
single-unit rate method, parametric cost modeling methods and
system/elemental cost analysis
e) Cost Estimator: the user who employs all the other element in
making an estimation and applying judgments during the estimating
process

8. Before the analysis can begin, the project costs need
to be adjusted or normalized (Ji et al., 2010;
Phaobunjong, 2002). Relevant data is extracted from
historical project cost. The data that are needed for
adjustment are a city cost index to quantity the
variability in project cost due to inflation (Sonmez,
2004).

9. Cost index are fundamental to cost planning since they provide a valuable
insight into changes in the cost of an item or group of items from one point
in time to another (time series). According to Ferry et al. (2010),
Consumer price index (CPI) can represents the ratio of exchange between
money and a basket of consumer goods. CPI published by Statistic
Indonesia (Badan Pusat Statistik, BPS) is a statistical estimate constructed
using the prices of a sample of representative items (goods and services)
whose prices are collected periodically. Construction cost index (CCI;
indek kemahalan konstruksi) that also published by BPS is more
appropriate to used because an indicator of the average cost movement
over time of a fixed basket of representative goods and services related to
construction industry. Moreover, CCI was deemed more suitable in the
sense that it more reflects price changes in construction

10. Dimana:
Cj = Cost at location j
Ci = Cost at location i

11. Regency/City 2010 2011 2012 2013 2014 2015
Kab Kepulauan Mentawai 111.73 112.88 176.09 187.76 181.95 162.9
Kab Pesisir Selatan 92 91.10 94.74 95.23 95.86 99.21
Kab Solok 85.38 87.10 85.45 91.63 92.31 94.71
Kab Sawahlunto/Sijunjung 87.47 85.82 96.54 101.39 101.48 92.82
Kab Tanah Datar 84.68 86.23 88.11 95.16 95.3 90.43
Kab Padang Pariaman 84.95 86.39 91.72 102.49 100.40 91.18
Kab Agam 88.34 92.31 98.68 97.44 99.60 91.44
Kab Lima Puluh Koto 85.42 84.22 94.51 96.41 98.96 87.74
Kab Pasaman 85.76 85.60 86.71 98.37 96.07 88.22
Kab Solok Selatan 85.97 84.13 80.92 98.05 95.25 101.97
Kab Dhamasraya 86.82 83.51 86.78 94.00 96.78 91.44
Kab Pasaman Barat 90.63 90.02 92.99 95.18 99.08 101.29
Kota Padang 82.83 84.10 104.82 101.94 100.68 97.27
Kota Solok 85.08 84.42 91.41 99.56 96.45 101.51
Kota Sawah Lunto 85.47 83.86 80.56 93.49 91.55 95.42
Kota Padang Panjang 86.02 84.75 87.05 98.32 97.16 98.01
Kota Bukittinggi 86.93 88.83 94.71 100.28 99.05 94.04
Kota Payakumbuh 84.9 84.86 88.71 98.05 99.08 88.33
Kota Pariaman 83.21 82.90 89.82 95.7 89.96 96.78

12. In economics, inflation is a sustained increase in the general price level of
goods and services in an economy over a period of time ( Blanchard, 2000).
Inflation affects economies in various positive and negative ways. The
negative effects of inflation include an increase in the opprtunity cost of
holding money, uncertainty over future inflation which may discourage
investment and savings, and if inflation were rapid enough, shortages of
goods as consumers begin hoarding out of concern that prices will increase
in the future. Positive effects include reducing the real burden of public and
private debt, keeping nominal interest rates above zero so that central banks
can adjust interest rates to stabilize the economy, and reducing
unemployment due to nominal wage rigidity (Mankiw, 2002).

13. Year Inflation (%)
2006 8.05
2007 6.90
2008 12.68
2009 2.05
2010 7.84
2011 5.37
2012 4.16
2013 10.87
2014 11.90
2015 12.74

14. To convert cost from one time (year) to another
year, the following formula was used