### PROBLEM SOLVING TECHNIQUE—Root Cause Analysis

During college, we solve a lot of problems. Mathematics, physics, machine design and thermodynamics were just a few examples. The good thing about these problems is that usually:

1. All needed information and parameters were given. All you have to do is to solve it using formulas and equations.

2. We are sure that the question has an answer.

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3. When you already find the correct answer, the problem is done.

That’s the good thing about solving problems theoretically. But when it comes to the actual work, everything is completely different. Some actual problems in the work are:

PIPING: “the pressure on a particular pipe is usually high”

MANUFACTURING: “the dimension of the parts coming out of the machine is off-spec”

FARMING: “the crops do not yield good fruits.”

EDUCATION: “the students’ score dropped dramatically”

In contrast to college problems, actual work problem are one or all of the following.

1. There’s none or insufficient information or parameters known. The “given” or parameters were all part of the problem itself. You have to conduct research and tests to find out the important parameters to be considered.

2. Sometimes, there are problems that has no answer or nearly impossible to answer.

3. Finding the answer to a specific question will lead to more questions and will reveal the complexity of the problem you once thought to be simple.

Root Cause Analysis

One common error in problem solving is trying to solve the effect rather than the root cause. The root cause is different from just an ordinary “cause” because the latter can also be on itself, an effect of a deeper cause. Digging into the base or the root of the problem is what refered to as root cause analysis. Solving just the effect is a waste of time because the real source of the problem is not fixed. The effect will keep on coming back or will just take another form. Solving just the effect is like curing a symptom rather than the true disease.

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Root cause determination is the first step before thinking of solving a particular problem. In some cases, the problem is so complex that it already branched out to many sub issues. This makes root cause determination even more difficult.

Good thing to know that there are many techniques to ease the process of root cause analysis. On the next article, we will discuss two of the known techniques used in solving tough problems. They are:

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Fishbone Diagram and 5 Why’s

### SOLUTION TO MECHANICAL BOARD EXAM PROBLEMS: Power Set-1

Here are the solutions to board problems given at Power Subject Set-1. If you do not understand anything, feel free to write a comment voicing out your concern. I'm still looking for better ways to present my solution. I still don't know how to present equations and mathematical symbols with blogger. Please bear with me. 1. An automobile tire is inflated to 32psig pressure at 50 degree F. After being driven, the temperature rises to 75 degree F. Determine the final gage pressure assuming the volume remains constant. (Electrical Engineering Board Exam Problem) Solution: Since volume is constant, use Charles’ Law on constant volume processes. P1/T1=P2/T2 Note: P and T should be absolute. (32+14.7)/ (50+460) =P2/ (75+460) P2=48.99 psia Converting back to gage pressure, P2g=48.99-14.7 P2g=34.29 psig 2. Four hundred cubic centimeters of gas at a pressure of 740 mmHg absolute and temperature of 18 degree C undergoes a process until the pressure and temperature be

### PAST MECHANICAL BOARD EXAM QUESTION: Machine Design Set-1 (solutions and answers)

The following are the solutions and answers to MODIFIED PAST MECHANICAL BOARD EXAM QUESTION: Machine Design Set-1 posted on this blog last Saturday, November 14, 2009. Again, I want to stress out that most of the questions here are modified from its original form for the purpose of improving the question. Past Mechanical Engineering Board Exam Question Number 1 A 4 inches diameter short shaft carrying 2 pulleys close to the bearings transmits how much horsepower if the shaft makes 120 rpm. A.200HP               B. 199 HP C.198 HP               D. 202 HP P = (D3N )/38 -- for mula for short shafts from PSME code P = (4)3(120)/38 P= 202 HP Past Mechanical Engineering Board Exam Question Number 2 An instrument that measures the hardness of the work piece in terms of elasticity. a. Durometer b. Scleroscope c. Mohs's Scale d. Brinell Tester Source: Machinery’s Handbook

### BOARD EXAM TIP: Which Review Center?

First of all, I would like to apologize for a long time I haven't posted anything but introduction. The reason for that is I'm busy optimizing the design of this site. I'm hoping that the make over is good. Anyway, I would like to dedicate this article to those who are going to take/retake the board exam this coming October. My sincere wish that you bring out the best among yourselves and may the deserving ones pass the exam. Going back to the One-Million-Peso worth question: "Which review center should I enroll?" , I would like to answer that in the most unbiased way I can. Of course, I'm only human and I had also my preferences but I will try my best to hide it. To start with I will enumerate some of the prominent review centers that offer board exam reviews for mechanical engineering in the Philippines. 1. Alcorcon (Cebu & Manila) 2. Excel (Cebu & Manila) 3. Linx Engineering (Manila) 4. MERIT (Manila) 5. PRIME (Cebu) 6. RLB's