2013년 6월 8일 토요일

The Goal by Goldratt

I read this book mainly because it was assigned as assignment.
Its actually great book teaching you how to minimize the cost and optimize your process using TOC and other concepts. I had to write a book review on this book and here is what I wrote:

The goal by Eli M. Goldratt is a novel focused on Alex Rogo, who is a production manager of a company having hard time. Alex is introduced to a concept of TOC after meeting his old guru Jonah. The intention of theory of constraint, which Goldratt's most famous for, is to improve the system by identifying and eliminate the constraint that is holding back the company's performance hence increases their throughput. TOC states that, running areas with higher capacity will not increase throughput of system. Management should find are with lowest capacity, which is their bottleneck, and try to increase its capacity. Goldratt introduces 5 step models to achieve that. First, company should identify the constraints. Second, decide how to exploit constraints. Third, subordinate everything else to the above decision. Fourth, elevate the system's constraint. Lastly, if the constraint from first step is broken, go back to step 1. Throughout the novel, Goldratt tries to explain and prove the importance of TOC and his principles. In addition to these 5 steps, one should ask these three questions too. What to change? What to change it to? How to cause the change? These three questions should go along with the 5 step model when incorporating theory of constraints in business. Rogo believed that these three questions were essential to managers in order to successfully understand and apply theory of constraints. In the novel, Rogo was successful in fixing company's problem and promoted. These concepts and ideas are really relevant to any type of business and any professions. Because of the economy factors of nowadays, many companies are trying to minimize their costs and resources and I believe "The Goal" is the one of must read book that will help people to achieve it.

Decision making using decision tree analysis





Decision Tree
And
Analysis
PREPARED BY
Young Kim
IE417 Section 1 Spring 2013


REVISION PAGE:


REVISION
        DATE                           DESCRIPTION
      N/C                        06-05-2013                  Initial Release
1.0  Introduction:

The following report demonstrates decision making analysis using decision tree.

2.0  PROBLEM

CEO of Cerebrosoft, Charlotte Rothstein, is faced with a situation where her company needs to make decision whether to launch the product or abandon it. When decided to launch it, they can go with a price of 3 categories, $50, $40, or $30. Once again, with $50 pricing range, they can choose either to hire researcher or not.

3.0  OBJECTIVE

To use technique of decision tree and probabilities to choose optimal scenario for Cerebrosoft with maximum expected revenue.

4.0  REFERENCE DOCUMENTS:

A. Operational Research Applications and Algorithms 4th Edition, Wayne Winston
B. Lecture slide

5.0  REFERENCE SOFTWARE:

A.      Microsoft Excel
B.      Microsoft Word

6.0  ASSUMPTIONS & RATIONALE:

-          When abandoned, their initial investment of $800000 is lost
-          No marketing, including advertising, or annual support cost of $50000 is encountered in calculation of revenue.

7.0  Decision Tree and Probabilities
Below is embedded file of Decision Tree Diagram and Probabilities Calculation
(I actually have files 4 files embedded in this documents, but its not visible here, hence i will just post it here :))

Without Researcher


-

                         With Researcher



d

EVWPI(expected value with perfect information tree diagram)



Above is the probabilities




 Note: The expected value of node that contains multiple scenarios with probabilities in each tree diagram was calculated by multiplying previous expected value with the corresponding probability.

8.0  Findings

As you can see with the decision tree diagram without researcher, setting product price at $50 will give maximum expected revenue of $715,000 for the first year. If we take in account of support fee of $50,000, then our expected revenue of first year will be $665,000. From the following years, under the assumption that our probabilities stay same, we will have expected revenue of $1,465,000 since our initial investment of $800,000 is made up from first years revenue. The expected revenue from the following year will be

When it comes to decision of whether to hire researcher or not, our expected revenue from hiring researcher is determined to be $705,000.

EVSI is calculated by using equation EVSI = EVWSI – EVWOI which is ($705000+$10,000) - $715,000
EVSI is determined to be = $0.

EVPI is calculated by using equation EVPI = EVWPI – EVWOI

EVWPI is calculated by calculating expected maximum value for each state.
EVWPI = 0.2*$625,000 + 0.7*$725,000 + 0.1*$825,000
EVWPI is determined to be $715,000

EVWOI is calculated from calculation in EVSI which is determined to be $715,000
EVPI = $715,000 - $715,000 = $0


9.0  Conclusion


From the analysis, we can conclude that company should not hire a researcher and set the price of the product at $50 to have maximum expected revenue for first year of $715,000 before support investment of $50,000. This conclusion is drawn from the value of EVSI and EVPI. The minimum desired EVSI value is $10,000 which is the amount that company is willing to pay for the research. The EVSI calculated tells that the amount of research price that company is should pay to have extra expected value is $0, which means that as soon as price of research goes up, the expected profit of company drops by same amount. In other words, unless it is free to conduct the research, it is not worth doing it. The EVPI tells that the amount of money that company is willing to pay to know the trends is $0. Hence, in summary of this analysis, the company should not invest any money on extra information and set the price of product at $50 to maximize their expected profit.