1.       Problem Definition

My colleague and I are planning to implement phone survey for data collection for our study’s sample. Prior the real survey, we have to test the phone questionnaire whether the survey can be finished in 20 minutes. The questionnaire consists of 30 questions, so we picked random respondents to examine how long it takes to finish the survey.

Problem Statement: does the duration of the survey within the expected duration?

2.       The Feasible Alternatives

Based on the problem, I identify three possible results:

  1. The result shows the actual duration of the survey is the same with the expected duration.
  2. The result shows the actual duration is less than expected duration.
  3. The result shows the actual duration is more than the expected duration.

3.       Tools and Technique

To answer the problem, several steps to solve the problem:

  1. Collect sample data;
  2. Determine number of class and frequency;
  3. Draw the histogram from the frequency table; and
  4. Interpret the histogram.

4.     Selection of the Acceptable Criteria.

Table 1 shows the frequency table which we collected from respondents.







Table 1: Frequency Table

Then, we decided the number of classes that contribute to our analysis, next construct the frequency table.






Table 2: Number of Classes and Frequency

Then, we draw the histogram.

Figure 1: The Histogram

Figure 1 shows the frequency within 10-15 minutes is the highest. We are confidence the survey’s respondent can finish the interview less than 20 minutes with current questionnaire.

5.       Post-Evaluation of the Result

Based on the calculation above, the result shows the chance of interview can be finished in 10-15 minutes is higher. We have to scrutinize the current questionnaire and make sure it collects the information we needed for the report.

6.       References

Brassard, M. & Ritter, D. (2010). The Memory Jogger 2: Tools for Continuous Improvement and Effective Planning, pp. 91-100.

Histograms: Construction, Analysis, and Understanding. Retrieved from: http://quarknet.fnal.gov/toolkits/ati/histograms.html

Henning, J. 2009. Do phone surveys have a future? Retrieved from: http://www.research-live.com/features/do-phone-surveys-have-a-future?/4000692.article

Vicente, P., Reis, E., & Santos, M. Using Mobile Phones for Survey Research: A Comparative Analysis between Data Collected via Mobile Phones and Fixed Phones. Retrieved from: http://homepages.wmich.edu/~wmartz/assets/mobile-phones-survey-research.pdf


W13.0_Ary_HV Transmission Line Losses Reduction – Economic Analysis using PW Method

Problem Recognition and Definition

Power loss in high voltage transmission line has a linear relationship to the loads and has exponential relationship to the current flows in the lines. Several methods available in compensating transmission losses and one the most popular method is utilizing Static Var compensation (SVC) equipment installed at the load side. It is important to analyze the econimical benefit of SVC implementation to solve transmission line loss problem.

Possible Alternatives

As mentioned above, SVC is the most practical used in electric transmission & distribution system while another system has been introduced (new technology) by using AC-DC-AC converter equipped with SVC system.

In this economic analysis both alternatives will be analyzed based on cost savings given and opportunities available from the features of these equipment.

Analysis and Criteria

The attached graph showing increasing trend of MVAr supply from hydro power generation through with distance about 30 kilometers long from the center of loads.

Figure 13-1. MVar generated trend

The average MVAr delivery is 80 MVAr and in this study, reduction to half of this value is technically accepted. Loss from 40 MVAr transmission line is worth to $499,000 per year.

Below are two alternatives with technical capability of both equipment and opportunities provided if the equipment installed.

SVC installation is designed to reduce MVAr delivery from power generation while the AC-DC-AC converter (DC Link) does the same with additional capability to transfer active power (MW) from hydro bus to thermal power station bus system. It provides extended opportunity to shutdown diesel generating plant.

Cost comparison of two generating stations is figured below and will be used as a basis to calculate cost savings:

With opportunities (savings) from the two alternatives are figured below:

And summarized data for this analysis is shown on below table

Table 13-1. Basic data of two alternatives

Equivalent worth method will be used to select the best economical option selected for implementation. And alternatives with the highest PW value at defined MARR will be proposed to management.

MARR 25% will be used in this study with 10 years useful life of equipment.

Assessment Result

Below figure shows calculation result among two alternatives. Alternative 1 (SVC) provided negative PW value and alternative 2 (DC Link) provide positive (higher) PW value despite higher investment and yearly operating cost compare to the 1st alternative.


Table 13-2. Study result using PW method

Post Evaluation

Extended economical analysis using another method can be done in separate page to provide strong justification. More technical study and alternative provided to solve the problem might be done and obtained as part of the next study.


  1. Sullivan, W.G. Wicks, E.M. Koelling, C.P (2012). Engineering Economy, Fifteenth Ed. (chapter 6, page 233-239).New Jersey: Prentice Hall.
  2. Deng, Yongan. Reactive Power Compensation of Transmission Lines. Concordia University: retrieved from: http://users.encs.concordia.ca/~lalopes/Courses/IGEE401-F07/TL_Compensation.pdf
  3. ABB. ABB Advance Power Electronic. ABB Switzerland Ltd. Retrieved from: http://www05.abb.com/global/scot/scot232.nsf/veritydisplay/d20bc6e606717f9bc12576c40043ea95/$file/PCS%206000%20STATCOM_INCO_EN.pdf

W14_IQB_Theories of Motivation

I was in a Leadership workshop when I found out that there are theories of motivation which I never heard before until I found them in the pre exam pass by my mentor. There are many theories regarding how to motivate others but the most prominent theories are:

  • X and Y theory
  • 2 Factor theory
  • Equity Theory
  • Expectancy theory
  • Goal Setting theory

X and Y Theory

This theory was proposed in early 60’s by Douglas McGregor, an American social psychologist, from his book “The Human Side of Enterprise”. McGregor suggest that there are 2 style in managing people, using “authoritarian style” or known as X theory which the management will use power to direct his/her subordinate to achieve the organization’s goals. He/she will give a detail direction what and how to do things. It will result in an un-ambitious, lack of responsibility subordinate. All responsibility will be under the manager. No sense of belongings to the result of the work from the subordinate.

The other style is “participative management” or known as Y theory, which the management allows his/her subordinates to express their ideas, self directed and self control. The management will only give a general objectives and timeline/duration. The subordinates will be responsible to achieve the objectives.

Those 2 (X and Y) theories are well-matched to certain conditions/level of organization. When we face the situation where the subordinates is the lowest level of organization with inadequate knowledge and capability, then use the X theory, give them detail direction and closely monitor the progress. But for the medium level of organization where the knowledge and capability were adequate, then use the Y theory, give them the objectives and general direction and let them solve it.

2 Factors Theory

 Herzberg shares his theory about the cause of employee’s satisfaction and dissatisfaction. In his theory, he explains that there are 2 factors which influence employee’s motivation. They are motivation and hygiene. Motivation factor is the factor that the absence of this factor will not result in dissatisfaction of the employee but when this factor provided by the company, it will heighten the employee’s motivation. This factor included status, recognition, bonuses, promotion etc.

And not in the opposite of the motivation factor but different factor that gives effect to employee’s motivation is hygiene factor. Hygiene factor is factor that the absence of this factor will result in dissatisfaction of the employee but when this factor provided by the company there will be no change to their motivation since this is the basic needs. This factor includes wages, salary, security of works, quality of inter personnel relations etc.

Equity Theory

This theory was presented by John Stacey Adam in 1963, it said that people will be highly motivated when he receive fairly and equally treatment in every aspects of his life. There are 3 elements in equity theory, they are: 1. Input, are every aspect that given by the worker such as effort, skills, commitment, and hard work etc, 2. Outcomes, are every aspects that the worker thought that those are his rewards such as payment, salary, wages, and promotion etc, 3. Comparison person, is individual whose worker compare his ratio to. 

 The equity theory is dependant to comparison between an individual ratio of reward/investment (input/outcomes) to ratio by other (Comparison Person) in similar condition. He/she will naturally compare his/her ratio to other ratio which any inequity due to comparison will result in disappointment worker.  

Expectancy Theory

This theory was brought by Victor H. Vroom in 1964, it said that an individual tend to motivated when he knows that in the end there is something he can expected to become. This theory is based on 3 aspects, they are: 1. Expectancy, is perception that the current effort will lead to good performance, 2. Instrumentality, is perception that the performance will lead to reward, 3. Valence, is the expected value will be received.



From the above theories, we can conclude that every theory has similarities to each other. There are many ways to encourage the worker but all theory emphasize that reward id the easiest way to motivate the worker.


Scholl, Richard W., “Motivation: Expectancy Theory”, 2002. Retrieved from http://www.uri.edu/research/lrc/scholl/webnotes/Motivation_Expectancy.htm

Kurniawan, Arifianto, “Theory : 2 Factor, Expectancy, Equity”, retrieved from http://www.scribd.com/doc/54889324/Case-Study-2-Factor-Expectancy-Equity-Theory

“Douglas McGregor: theory x y” retrieved from http://www.businessballs.com/mcgregor.htm

“Motivation in theory – Herzberg two factor theory” retrieved from http://tutor2u.net/business/people/motivation_theory_herzberg.asp

“Equity Theory on Job Motivation” retrieved from http://www.businessballs.com/adamsequitytheory.htm

W18_RW_Mutually Exclusive Project Selection with Benefit Cost Ratio

Disclaimer: All value in this blog is not real, it used to simulate to determine the economic life calculation.

Problem Statement:

My company has 5 alternatives investment projects with certain cost and benefit calculated previously, the data shown in the table below:

My boss ask me to compare those alternatives by using Benefit Cost Ratio (B/C) to determine which alternatives that has B/C>1.1

Acceptable Criteria

  1. Alternative which has B/C>1.1


Tools and Techniques:

From Sullivan’s Engineering Economy 15th Edition, chapter 10, section 10-9, Comparison of Mutually Exclusive Project.

Step 1. Rank the Cost of Alternatives from the smallest to the largest cost.

Step 2. Calculate the B/C ration from the smallest cost

Alternative E has 1.13>1.1 (acceptable) now it became a baseline to compare with other ranked alternatives.

Alternative D: (benefit D – benefit E) / (Cost D – Cost E) = 1.28 >1.1 (acceptable) now it became a new baseline

Alternative B: (benefit B – benefit D) / (Cost B – Cost D) = 1.25 >1.1 (acceptable) now it became a new baseline

Alternative A: (benefit A – benefit B) / (Cost A – Cost B) = – 4.5 <1.1 (not acceptable)

Alternative C: (benefit C – benefit B) / (Cost C – Cost B) = 0.33 <1.1 (not acceptable)


The conclusion:

From the above alternative comparison which mutually exclusive alternative using the incremental analysis we know that Alternative B has B/C=1.25>1.1, and this alternative B is recommended.



Sullivan, W.G., Wicks, E.M., Koelling, C.P. (2009). Engineering Economy, Fifteenth edition. Pearson International Edition, 2012, Chapter 10, pages 436.

“Mutually Exclusive Alternatives” retrieved from http://www.oup.com/us/static/companion.websites/9780195161526/interactive/MEA/MEAIntro.htm

W17_RW_When Should I Replace my Car

Disclaimer: All value in this blog is not real, it used to simulate to determine the economic life calculation.

Problem Statement:

I just bought 3 years old used car, this car was bought with $20,000 it was in good condition, from the manual book I see there is a potential to replacing some major spare part beside the routine preventive maintenance. The detail data shown in table below, assume I have 15% personal interest rate per year. When should I replace this car?

Feasible Alternative:

  1. Continue using that Car until it cannot be used
  2. Replace the car at certain year to get the best economic value

Tools and Techniques:

From Sullivan’s Engineering Economy 15th Edition, chapter 9, section 9-6, Determining the economic life
Selection Criteria:

Equivalent Uniform Annual Cost (EUAC) > total margin cost is the best choice.


Deterimine the potential loss in Market value and cost of capital to get the total marginal cost.

Marginal Cost = Major Maintenance + Preventive Maintenance + Loss in Market Value + Cost of Capital

And now calculate the EUAC with 15% MARR.


The conclusion:

Using the car until it scrap is not a right choice at it will drain your pocket for increasing maintenance cost and lowering the market value. Sell the car at the 2nd year and purchase the new car is a good choice, in term of economic value it is the optimum years where we can get the reasonable market value compare with the maintenance cost, where the total Marginal cost is less then the EUAC (15%)


Sullivan, W.G., Wicks, E.M., Koelling, C.P. (2009). Engineering Economy, Fifteenth edition. Pearson International Edition, 2012, Chapter 9, section 9-6 pp 391.

“Operation Research Model and Methods” retrieved from: http://www.me.utexas.edu/~jensen/or_site/models/supplements/netmodel/S1_ecolife.pdf

“Equivalent Annual Worth” retrieved from : http://www.oup.com/us/pdf/engineeringecon/Chapter06.pdf