Certification of vibration analysts has been one of Canadian Machinery Vibration Association’s (CMVA) functions for many years. Questions remain, however:
Performance objectives are the answer. This paper will define them, show how they apply to the condition monitoring business, relate them to the ISO 18436-2 standard on which we base our certification, and show how they can be useful in related situations. It will also describe the procedures used to develop the ones CMVA uses.
1. INTRODUCTION
The quality of vibration analysis and condition monitoring depends to a very large extent on the quality of the people who carry it out. It does not matter how good the monitoring equipment is or even how committed management is; the program will fail unless it is run by capable dedicated people. What can be done to ensure the availability of capable, dedicated people? Performance objectives are the answer.
2. THE NEED
2.1 Plant Requiremens
Nowadays, no one questions the benefits of a good predictive maintenance system. Plenty of evidence from a wide variety of sources has demonstrated the benefits time and time again. The operative word, though, is good. Three factors, primarily, govern the quality of the program:
Of these, the first two are beyond the scope of this paper, and helping ensure the third is our focus.
2.2 Personal/Personnel Requirements
Individuals need to know their tasks, and they need to be able to demonstrate that they know them. This statement is true particularly in the vibration business, since the diversity of educational background, training and experience is so broad. There is no single recognized degree or diploma course that everyone studies, which means that qualifying for the job is difficult.
Similar problems exist for companies who need to hire the appropriate expertise. How can they know what type of individual is required for their particular job? How can they even write the job description, since the speciality is so narrow?
2.3 Course Development
Vendors have stepped into the breach, and many do an excellent job of preparing personnel to work in condition monitoring. They often offer courses in how to use their equipment, and they may also offer general courses aimed at improving theoretical knowledge.
The vendor is offering his own course materials and instruction, and his own progression from course to course. A Level 1 course from one vendor may not meet the pre-requisites for taking a Level 2 course from another vendor, since the courses are proprietary and therefore tend to preclude co-operative development. Consistency, though, requires further work.
3. A STEP IN THE RIGHT DIRECTION: ISO 18436-2:2003(E)
3.1 What is ISO 18436-2?
ISO 18436-2 is an International Standard, titled Condition monitoring and diagnostics of machines, Requirements for training and certification of personnel
Part 2: Vibration condition monitoring and diagnostics. It divides the requirements for training and certification into four categories, and demands that those who certify at a higher category be responsible for skills at the lower categories.
3.2 Development of the ISO Standard
ISO 18436-2 was prepared by the International Organization for Standardization, which is headquartered in Switzerland. The work is done by representatives from various countries, and in this case, Canada took a lead role in the development. The committee has worked for several years on a draft standard, and the actual standard was finally published November 15, 2003.
3.3 Availability of the Standard
CMVA currently has a licence to post the standard on www.cmva.com , and members can download it for personal use from the Members Only section of the website. It is also available from IHS Canada, 1 Antares Drive, Suite 210, Ottawa, ON, K2E 8C4, Phone 800-267-8220 ext 431 Fax 613-237-4251.
4. FURTHER DEVELOPMENT
4.1 Nature of the Standard
As mentioned above, ISO 18436-2 is an excellent first step, but it also has limitations. It needs to be extended, in order to meet the needs defined in Section 2.
For example, the first major subject is Principles of Vibration, and it calls for course instruction as follows:
Category 1 - 6 hours of a 32 hour course
Category 2 - 4 hours out of 38
Category 3 - 2 hours out of 40
Category 4 - 4 hours out of 64.
It goes on to name narrower topics, to be covered at each level. For example, Categories 1, 2, and 3 are all supposed to study basic motion, period, frequency, amplitude, displacement, velocity, acceleration, units, unit conversions, time and frequency domains, natural frequency, resonance, and critical speeds. Higher categories are expected to deal with additional topics.
But how much is enough for each category, and how much is too much?
4.2 Course Development Based on ISO 18436-2
Now, imagine that you are a course developer beginning to design a series of courses to teach the requirements for certification at each level.
You have to consider the student’s background, and for Categories 1 & 2, the recommendation is at least a secondary school graduation, and six months experience. The obvious corollary is that your student may have no prior training in the field at all.
You also have to consider the stated objective of each category. For Category 1, that is to perform a range of simple single-channel machinery vibration condition monitoring and diagnostics of machines activities and for Category 2, that is to perform industrial machinery vibration measurements and basic vibration analysis . . . . When it comes down to determining course content, those two objectives are not sufficiently different to enable standardized course development by individuals who are working separately. For example, one course developer could quite reasonably include trend analysis in Category 1, and another could decide that trend analysis is beyond the scope of Category 1 and belongs in Category 2, especially since you have only 32 hours to teach neophytes everything they need to know to carry out their tasks appropriately.
4.3 Self-Study Based on ISO 18436-2
Self-study has similar limitations. The purpose of dividing the requirements into four categories must be to enable a gradual progression of knowledge and capability, while ensuring that lower category individuals can carry out their more limited tasks properly. If I sit down to study for a certification exam, how can I tell how much I have to master, based on the standard? I can’t. If I know enough about the field of vibration to be able to make those judgements, I should be teaching the material, not taking it.
4.4 Setting Exams Based on ISO 18436-2
People setting exams have the same kinds of problems. Is this a reasonable question for this category? Which questions should be moved to a higher or lower category? The objective of the exam is not to trip people up, or to exclude people; it is to certify those who have mastered the requirements, but how do we know what those requirements are?
4.5 Evaluating Courses
There are many reasons to take courses, and many courses to take. No one would suggest that every course should help the candidate pass a certification exam.
However, if passing such an exam is the goal, and taking a course is the means, you need to be sure that the course you are considering is the right one for your purposes. A key step would be to look at the Performance Objectives for that category, determine which ones you really want to master during the course, and then compare courses on that basis. Ask the course providers, and ask their references, and get an idea for yourself if a particular course will meet your needs. Training budgets are tight let’s make sure they are well spent.
5. PERFORMANCE OBJECTIVES
5.1 Definition
A Performance Objective is one that defines the performance expected of the individual, in real terms. It is action-oriented. Others can observe that performance, and determine whether it meets the objective. It is clear and obvious. It is not enough to have an understanding; that may or may not mean that the person can perform the task. The performance of the task itself is the issue.
5.2 Example
Everyone has either been to school or sent children to Grade 1, and probably everyone has assumed that the school will teach them to read. One would hope so. However, learning to read is not a performance objective. It is way too vague and wishy washy, and if it the only objective related to reading, its accomplishment by any student will be an accident.
One example of a performance objective related to reading is this:
During the first two weeks of school, students will master the letter A:
Given the above objective, and also given that the teacher’s evaluation depends on whether those students master that objective, chances are excellent that it will be achieved. The students may not learn to put their rubber boots on when it rains, and they may not do very well at collecting money for the March of Dimes, and they may not even play nicely with their peers, but they will learn the letter A. Assuming there is a complete series of properly defined and developed performance objectives that all lead toward mastering reading, those students will learn to read. People actually like to perform when they know what is expected of them.
5.3 Application to Vibration Training and Certification
The same sort of performance objectives can be related to vibration analysis. For example, instead of saying that Category 1, 2, and 3 all have to spend some time studying basic motion, and leaving it at that, we write one (or several) performance objectives. In this case, one could be for Category 1, observe a periodically vibrating item such as a pendulum or spring-mass system and draw the displacement, velocity, and acceleration curves associated with it.
The key advantages are:
Clearly, this is a simple example. Clearly, writing a complete set of performance objectives is a difficult task. However, the benefits are so clear that the task is essential.
6. END USER BENEFITS
In many cases, end users create job descriptions partly by demanding a certain level of education. (For jobs A, B, and C, we need a mechanic, for Jobs D and E we need a millwright, and for Job F we need a mechanical engineer.) Everyone understands the background in each case, and can use it as a basis for on-the-job training.
In the case of condition monitoring and vibration analysis, those definitions are much less clear. Undoubtedly, engineers could do routine data collection and vibration analysis, but would they? And even if they would, are they providing the most benefit to the company by doing those tasks? Moreover, it can be demonstrated within our own membership that quality programs (defined as programs that conform to requirements) can be carried out by people of widely diverse backgrounds. But again, when it comes to hiring, training and supervision, where do you start?
Performance objectives, with or without the associated certification, provide the necessary framework.
Even if the performance objectives developed by CMVA are not exactly what are needed in your particular circumstances, they go a long way toward making sure you have covered everything and that necessities don’t slip through the cracks.
7. PROCESS
CMVA is in the process of defining performance objectives for each category of personnel, as defined in the ISO standard. The process is on-going. We are trying to make sure that everything in the standard is further defined by a performance objective, and in addition, we give due consideration to suggestions that the requirements for a particular category should be extended.
As an example, Category 1 is primarily concerned with good data collection, an essential component of condition monitoring programs. The committee decided that in order to be certified at Category 1, it is not sufficient to pass an exam. In addition, the candidate must have his data collection skills checked out in the field, in practice. This requirement is beyond the scope of the ISO standard, but it does not conflict with it.
CONCLUSION
The certification process has to exist because it benefits end users. Without end users, academics have no reason to teach and suppliers have no one to supply. One important way to benefit end users is to provide relevant performance objectives and facilitate their achievement.
By Val Zacharias, B.Ed. M.A. (Curriculum and Instruction), Executive Director, Canadian Machinery Vibration Association, Calgary, AB, T3G 3T2