Difference between Preventive Maintenance and Predictive Maintenance

    IATF16949 (and ISO/TS16949) requires preventive maintenance and predictive maintenance for the machines. This article will have a discussion about the difference between these two types of maintenance activities.

    First, let’s take a look at their definitions in IATF16949:

• Preventive maintenance: planned activities at regular intervals (time-based, periodic inspection, and overhaul) to eliminate causes of equipment failure and unscheduled interruptions to production, as an output of the manufacturing process design；
• Predictive maintenance: an approach and set of techniques to evaluate the condition of in-service equipment by performing periodic or continuous monitoring of equipment conditions, in order to predict when maintenance should be performed.

    Based on their definitions, the most critical difference between preventive maintenance and predictive maintenance is that the former is time-based and it is known when to perform the maintenance, while the latter is machine condition based and it is unknown in advance when to perform the maintenance.

    There are some analogies in our daily life for preventive maintenance and predictive maintenance. One analogy for preventive maintenance is the maintenance on your vehicle according to the period suggested by the manufacturer. And one analogy for predictive maintenance is the gas filling in your vehicle tiers: the tire pressure is monitored. Once the tire pressure drops down to a threshold, a light on your vehicle dashboard turns on to notify the driver that it’s time to fill gas into your tires.

    For preventive maintenance, one needs to define what should be done to the machines and what is the frequency for such actions. While for predictive maintenance, there’s an extra step: it should be defined first what conditions of the machine should be monitored.

    Below is a list of some typical examples of preventive maintenance and predictive maintenance.

Type of Maintenance	Typical Examples
Preventive maintenance	-         Replace a spare part of a machine periodically, if the life time of the spare part is fixed in days, months or years; -         Clean the machine weekly; -         Apply lubricant to a machine quarterly; -         Replace the cooling water for a machine weekly; -         Fill oil into the machine bi-weekly;
Predictive maintenance	-         Count the number of times a cutter is used and replace the cutter when it reaches the expected life time, if the life time of the cutter is determined by the times it is used. -         Monitor the product surface roughness and sharpen the cutting tool when the surface roughness goes beyond the control limit; -         Monitor the vibration of the machine and tighten the bolts and nuts when the vibration reaches a threshold; -         Monitor the gas pressure of a gas tank and replace the gas tank when the pressure goes below a threshold;

How to Calculate GRR%

    For GRR analysis on a measurement system, GRR% is used to determine whether the repeatability and reproducibility of the measurement system is acceptable for the purpose of measurement. It is calculated with Equation 1:

    In the AIAG’s MSA manual (4th edition), four different approaches are presented to determine TV based on different scenarios:

Accordingly, TV is calculated with the following equations:

    The above four approaches and the corresponding equations for TV may be confusing to many people who are in charge of MSA in their companies, and they may not be really clear of which equation should be used in actual cases they encounter when doing their GRR analysis. This article is intended to give some additional discussion and clarification about how to decide which equation should be used for TV and in turn GRR% calculation.

    To decide which equation to be used, one first needs to consider the purpose of measurement. In general, any measurement conducted on a process has two purposes:

1. To judge whether the measured parameter is within or out of the spec limit, for the purpose of OK/NG judgement or product control;
2. To decide whether the process is under control (without special cause) and whether the process capability (Cp and Cpk) and performance (Pp and Ppk) meet the requirements, i.e. for the purpose of statistical process control (SPC). 

1. When the measurement is for product control 

    When the measurement is for product control, one cares about the possibility of misjudgment. Misjudgment happens when the true value of a measured parameter is located near the spec limit, indicated with the gray region in the graph below.

The width of the gray region is determined by the variation resulted from the measurement system, i.e. the GRR of the measurement system (The width of gray region is 6 times of GRR. Outside this width, the possibility of misjudgment due to GRR is nearly 0). The wider the gray region is in respective of the tolerance (USL-LSL), the higher the possibility of misjudgment is. Therefore, in order to have a small possibility of misjudgment so that the measurement can really achieve the purpose of product control, the ratio between gray region and the tolerance 6*GRR/(USL-LSL) must be small enough. GRR% should hence be evaluated with the following equation, i.e. the 4th approach presented in the MSA manual: 

2. When the measurement is for process control

    When the measurement is for process control, one cares whether the obtained data can correctly identify the existence of special causes and whether the measurement can really reveal the true process capability (Cp and Cpk) and performance (Pp and Ppk). Let’s take a look at these two purposes respectively.

2-1. When the measurement is to identify the existence of special causes

    In AIAG’s SPC manual, it listed out 8 criteria to identify the existence of special causes, as shown below:

Among all the 8 criteria, the 1st one is mandatory, and the rest are optional. So the discussion here will be just based on the 1st criterion. 

    To identify the special causes with the 1st criterion, one needs to monitor whether there’s any data point out of the control limits (±3σp). It is similar to judge NG samples from good ones. The difference is that the former uses the control limits, while the latter uses the spec limits. To correctly identify the existence of special causes, one cares about the possibility of misjudgment (i.e. an under-control data point is misjudged as an out-of-control data point, or an out-of-control data point is misjudged as an under-control data point). This is determined by the ratio of the gray region around the control limits with respective to the width of the control limits, i.e. 6*GRR/(UCL-LCL). Therefore, GRR% should be evaluated with the following equation:

where σp is the process variation.

2-2. When measurement is to monitor the process capability or process performance

    For this purpose, let’s just see how GRR of a measurement system impacts the observed Ppk of a process. It’s similar for other index, including Cpk, Cp and Pp. 

    Ppk of a process is calculated with the following equation (please refer to P.133 of the 2nd edition of AIAG’s SPC manual)

where σp is the total process variation as observed from the measurement results. This observed process variation includes two sources: one is the actual variation of the process itself σ1, and the other is the variation from the measurement system, which is GRR. According to the property of the normal distribution

So Equation 8 can be rewritten as

It should be noted that Ppk as calculated above is the observed Ppk by the measuring process. It does not reflect the actual performance of the process. The actual Ppk should be calculated as below, without the variation from the measurement system in the denominator:  

Comparing Equation 10 with Equation 11, one can see that the larger GRR is, the bigger the difference is between the observed Ppk and the actual Ppk (the former is always smaller). In order to make process control effective, the observed Ppk must be as close as to the actual Ppk, so it causes no misjudgment on the actual process performance. In other words, GRR must be significantly smaller compared with σp, so that Equation 11 can be approximated with Equation 8. Therefore GRR% of the measurement system should be evaluated with the following equation:

This equation is equivalent to Equation 7. So for either purpose 2-1 or 2-2, it comes to the same conclusion, i.e. GRR% should be evaluated as the ratio of GRR with respect to the process variation.

    The process variation can be known or unknown when GRR analysis is conducted. Let’s now see how to calculate GRR% based on Equation 7 or 12 in both cases. 

    When the process variation is unknown, for example, GRR analysis is done when the process is still in design and development stage or the process has just undergone some changes and it has not been studied yet. In such a case, the observed process variation σp can be obtained with following approaches:

1. Select a group of samples from the process (It must be noted that the number of parts must be enough to cover the full width of the process variation) and measure the parts variation PV in this group. PV represents the true variation of the process, so the observed process variation σp, according Equation 9, is: 
   
   GRR%, hence, can be calculated with the following equation, i.e. the 1st approach introduced in MSA’s manual:

   
2. Use the process variation σp of a similar process, i.e. the 2nd approach:
   
   This approach should only be used when it’s not possible to obtain and do measurement on a group of samples representing the full process variation, i.e. the 1st approach is not feasible.
3. Use the target Pp or Ppk, i.e. the 3rd approach:

   

   Again, this approach should be used only if the 1st approach is not feasible.

    When GRR analysis is done when the process has already been studied and released to mass production, for example, the annual MSA after process release, the process variation is either directly known or can be derived from the other process index, and GRR% can be calculated with the following approaches:

1. The process variation is directly known, GRR% can be calculated with the 2nd approach.
2. When process variation is not known, but Pp is known, GRR% can be calculated with the 3rd approach. 
3. When the process variation is not known, but the variation of Xbar, i.e. or control limits of Xbar, i.e.is known, GRR% can be calculated with the following equation:
   
   This approach is not mentioned in the MSA manual
4. If a group of samples is available which represents the full width of the process variation, GRR% can also be calculated with the 1st approach, without using the existing data about the process. 

    As a summary, the table below lists up the scenarios what equations should be used for GRR% calculation：

做GRR分析时是否可以使用不合格品

      在网上看到有个问题：做GRR分析时，是否可以使用不合格品？这个问题的答案是不可以。以下是对于此答案的解释：
   
      进行GRR分析时，GRR%的计算可以根据不同情况采用三种公式（关于三种公式的解释，请参考另一篇文章）。其中，如果测量的目的是为了进行SPC管控，在尚未建立过程的控制限的情况下，GRR%的计算公式如下

此处整个分母代表的是用测量系统观察到的过程的总变化，包括测量系统引起的变化AV&EV和过程本身的变化PV（PV虽然被称为parts variation，但它由过程本身的能力决定，所以是过程本身变化的体现）。因为测量的目的是为了进行SPC管控，所以GRR分析时，需要评价的是测量系统的变化相对于受控状态下过程总变化的大小。如果进行GRR分析的样品中存在不合格样品时，PV将不再代表这个过程在受控状态下的变化（因为存在不合格，代表过程存在特殊因素，所以过程处于非受控状态），而是会大于处于受控状态的过程的变化。根据Equation I，因为PV变大，此时的GRR%将会比没有不合格品时候的GRR%来的小，造成对GRR分析结果的误判。

      另外，GRR%计算公式中的AV的计算公式如下

其中Xdiff是进行GRR分析的样品的平均值Xbar的最大值和最小值之间的差值。当存在不合时，这个差值会比没有不合格品的时候要大，从而影响AV的值，并进一步影响GRR%的值。

      综上所述，GRR分析时，不应该选择使用不合格品。

How to Use SPC for Process Control and Improvement

      SPC is a powerful tool for process control and improvement, but if it’s not properly used, it may cause extra burden to the owners of processes, but bring them with little benefit. To do effective process control and improvement with SPC, one needs to follow the three steps as described below:

1. Process Release

      This is done during R&D stage for transferring the process to mass production. A process must be evaluated and can only be released for mass production when it satisfies two conditions:

• The process is under statistical control. In other words, there is no special cause existed and the process is stable and predictable. The distribution of products produced by this process will be the same in the future. 
• The indicators of the process capability and performance meet the customer or internal requirements (e.g. many customers require Cpk>1.67).

      Now let’s see how the evaluation on the process should be done:

      1) First, collect >= 25 subgroups with a total of >=100 samples of the controlled parameter. The variation within a subgroup should be minimized, so the samples of the same subgroup are suggested to be taken from the same batch or lot, with the least variation in the impacting factors of the process (e.g. materials used, operators, equipment, processing parameters, etc). On the other hand, the variation between subgroups should be maximized. So a subgroup can be taken when the shift is changed, the material lot is changed, or the production line is restarted, etc.

      2) Calculate the trial control limits with the data points collected. Plot them in the control charts. Identify any subgroup which signals the existence of a special cause. Exclude these subgroups and repeat this step (more subgroups may be collected to replace the excluded ones if the total number of subgroups falls within 25). Actions should be taken to remove the special cause if it continuously exists in the process.

      3) When all the subgroups with special causes are excluded from the control charts, use the reaming subgroups to calculate the control limits and the indicators of the process capability and performance, including Cp, Cpk, Pp and Ppk, and see whether these indicators meet the requirements (e.g. whether Cpk>1.67).

      4) If not, take actions on the common cause to improve the process until the indicators meet the requirements.

      5) If yes, check the difference between Cp and Cpk. If there exists a big difference, it means the process average is significantly shifted from the process target, and a significant part of the process capability is wasted due to the shift . Actions should be taken to bring the process average close to the target.

      6) Also, it’s suggested to check the difference between Cpk and Ppk. If the difference is significant, it indicates the between-subgroup variation is significant, special causes exist and the process is not actually in statistical control. Actions should be taken to remove the special causes.

      After all the above steps, special causes originally existed in the process are removed (i.e. the process is now statistically controlled) and all the process capability and performance meet the requirements. The process can now be released for mass production.

      After the process is released, the control limits established after the above steps should be continually employed during the mass production. They should not be changed unless there’s intentional change in the process or the reason for the change is clear.

2. Process Monitoring

      With the control limits as established during process releasing, the process owner continues the data collection of subgroups, with the defined sampling frequency, sampling scheme and size of subgroups, and monitors:

• Whether the new subgroups indicate the occurrence of any special cause (the rules to identify the special cause can be found in P.75 of AIAG's SPC manual);
• Whether the indicators of process capability and performance fail to meet the requirements; 
• Whether the difference between Cp and Cpk or Cpk and Ppk is significant. 

      If the answer is YES to any of the above question, actions should be taken as discussed in Step 3)-6) in Step 1 Process Release.

3. Process Improvement

      Even the answers for the three questions in Process Monitoring are all NO, one should never stop there. One needs to study the process and take actions to improve the process, to increase the process capability and performance. The improvement of process requires actions on the common causes, and usually requires the resource support from the management team.

      Once the improvement actions have been taken, one needs to go back to Step 1 Process Release, do the evaluation on the process and start over again. As a most significant result from the process improvement, new and tighter control limits are usually established.

The Difference Between Cpk and Ppk

      What is the difference between Cpk and Ppk? How should they be properly used for process control and improvement? These are probably questions confusing many SPC users. This article will try to answer these questions.

      First, let’s compare the difference between Cpk and Ppk. Cpk is an indicator for the capability of the process, the best that the process can achieve, while Ppk is an indicator for the actual performance of the process. A process with, say, Cpk=1.67 may not show its full capability and only shows a Ppk below 1.67, say, 1.50. An analogy to this situation is a student who’s really smart and has the ability to become the top 1 student in the class (his capability), but it’s not necessary that he’ll become the top 1 student (his performance), for reasons such as less devotion than other students.

      Second, let’s see why Cpk is an indicator of the process capability, while Ppk is an indicator of the process performance.

      To answer this question, we must keep it mind that the first step for SPC control is to adjust the process and ensure it is statistically controlled. Meanwhile, for the sake of easy formulation, let’s assume that the process average coincides with the process target. In such a case

      In the above Equation I, (USL-LSL) is the accepted tolerance of the process, and σc the standard deviation of the measured samples (please be noted that it is the standard deviation of all the measured samples, not the average of the subgroups), an indicator of the total process variation. The higher their ratio (i.e. Cpk) is, the lower the chance is to produce a nonconforming product. For a process with a normal distribution and with the process target coinciding with the process average, the correspondence between Cpk and the defective rate (in terms of PPM) is given the following table:

      From the table, it can be seen that a higher Cpk results in a lower defective rate, indicating a better ability of the process in producing conforming products.

      In Equation I, σc is calculated with the following equation:

where Rbar is the average of the ranges of individual subgroups. Combining Equation I and Equation II, one can see that the capability of a process Cpk is determined by variation within each subgroup.

      At this point, one may wonder why the total process variation σc is only determined by the within-subgroup variation. How about the between-subgroup variation? To understand that, we must mention the precondition to evaluate the process capability again: the process is statistically controlled. For such a process, the between-subgroup variation is negligible (according to P.131 in the second revision of AIAG SPC’s manual, the between-subgroup variation is 0 for a statistically controlled process). Therefore, the total process variation, and hence Cpk, is only determined by the within-subgroup variation (please refer to the below image).

      In real life, however, a process cannot always be adjusted to statistically controlled state even there is no special cause detected in the control chart. Also, even if the process is in statistical control at the moment of evaluation, a special cause can occur at any future moment and take the process away from statistically controlled state. Therefore, for an actual process, its performance hardly shows its capability as indicated by Cpk. The total variation of the actual process consists of not only the within-subgroup variation, but also the between subgroup variation. The performance of the process, Ppk, is calculated with the following equation

where σp is total variation of the actual process, and it is the combined result of within and between-subgroup variation (please refer to the image below), and is calculated with the following equation:

where Xi is the data point and n is the total number of the sampled data.

      As a summary, Cpk is calculated for a process which is under statistical control. The between-subgroup variation is 0, and the process variation comes from within-subgroup variation only. The process in such state is the best performance that a process can achieve, so Cpk represents the process capability. On the other hand, Ppk is calculated for actual process which is not necessarily under statistical control. The process variation consists of both within and between subgroup variations. Therefore, Ppk reflects the actual performance of the process. Ppk can never be larger than Cpk.

      Finally, after understanding the difference of Cpk and Ppk, let’s consider how these two indicators should be used for process control and improvement. There’s no question that these two indicators should be monitored to meet customer or internal requriements (e.g. Cpk >1.67). Meanwhile, these two indicators should be monitored together and their difference is evaluated. A big difference between Cpk and Ppk indicates large between-subgroup variation, meaning special cause may exist in the process and actions should be taken to remove the special cause. Cpk and Ppk should never walk alone.

How to Decide What Analysis can be Exempted from MSA?

The AIAG's MSA manual requires that five types of analysis shall be done for MSA: bias, repeatability, reproducibility, linearity and stability. An MSA plan should cover all these five types for each measurement system appeared in the control plan as discussed in a previous article, unless it can be justified that certain analysis are not necessary. This article will discuss a couple of examples and explain how one decides what kind of analysis can be exempted from MSA.

Example I:

Caliper I is used for thickness check of materials A with a spec of 5+/-0.01mm. Caliper II is used for thickness check of material B with the spec of B 5+/-1mm. They are not used for any other measurements. In this case, Caliper I is used over a range around 4.99~5.01mm. Over such a small range, the impact of linearity to the measurement result is insignificant. On the other hand, Caliper II is used over a range around 4~6mm and the linearity of the measurement system could be a concern. Therefore study of linearity is not needed for measurement system of Caliper I, but is necessary for measurement system of Caliper II. 

Example II:

An electrical platform scale is used to measure the weight of each product before outgoing. There are two appraisers assigned for this measurement, but for an electrical platform scale, the appraisers should have no impact to the measurement result (all the appraisers do is just to turn on the machine and put the product on the scale. How they do these things do not change the measurement results), and hence in this case study of reproducibility is not necessary.

As a general rule, before deciding what kind of analysis can be exempted from MSA, one must first understand what variation the analysis evaluates. The table below is a summary:

Analysis	Variation Evaluated
Bias	Variation caused by all the factors of the measurement system
Repeatability	Variation caused by equipment itself
Reproducibility	Variation caused by different appraisers
Linearity	Variation caused by measurement range
Stability	Variation caused by time difference

When deciding any of the above analysis can be exempted, one must consider whether the corresponding variation evaluated by this type of analysis has any concern to the measurement results. If not, then the analysis can be exempted from MSA.  

How to Do Effective Quality Planning

      An organization’s quality management system cannot be effective without good planning. So how can an organization do an effective quality planning? One need stick to the following points:

1. It must be the top management who’s responsible for the quality planning.

      Quality planning shall always be coordinated and led by the top management. I have seen organizations which do the quality planning just by the management representative, who’s often the head of the quality department. In such organizations, the quality planning can seldom be effective. The quality management system must be well integrated into the organization’s business operation to make it effective and become a value adding system to the company. So the person leading the quality planning must fully understand the company’s strategy and the direction that the organization wants head to. This person must have integrated knowledge of the company’s overall performance, so that he/she can have a good perspective for what is expected to be achieved from the quality planning. So this role can hardly be replaced by anyone else.

2. Following things shall be done in quality planning according to ISO9001:2015

• Understand the internal and external issues of the organization;
• Understand the needs and expectations of the interested parties;
• Establish the quality scope;
• Identify the processes in the quality management system, establish the requirements and control of each process, and define the roles and responsibilities of each position in the processes;
• Establish the quality policy;
• Identify the risks and opportunities in the quality management system and propose actions to address these risks and opportunities;
• Establish the quality objectives (the objectives for the whole organization, for each department, for each quality process, for the effectiveness evaluation of actions taken to address the risks and opportunities, etc.);
• Propose the actions to ensure the achievement of the above objectives and allocate the necessary resources to support the effective implementation of these actions.

     Understanding of the internal and external issues of the organization, understanding of the needs and expectations of the interested parties, and risk & opportunities identifications can be done together, as explained in another article. Identification of processes is discussed here. Requirements and controls which shall be established for each process can also be found in my other blog.

      It must be emphasized here again that quality management system shall be integrated with the overall business operation of the company. So when doing the above planning, it shall not be a stand-alone event. It must serve for the achievement of the organization’s business targets. For example, when setting up quality objectives, the top management shall consider how the achievement of these quality objectives can help the achievement of the organization’s business targets. Otherwise, the quality objectives are meaningless.

3. Quality planning is not once a year event

      Quality planning shall not just be done once a year. An organization usually has multiple ways to review the effectiveness of its quality management system, such as management review, internal audit, customer satisfaction study, etc. Whenever such review is done, planning shall be done again, to see whether all the things done previously are effective, suitable and adequate, and to see whether objectives shall be adjusted and new actions shall be proposed.

How to Do Effective Management Review

How to Do Effective Management Review

ISO9001:2015 requires that management review shall be done at planned intervals to ensure the suitability, effectiveness and adequacy of the quality management system. Every organization does the management review if it wants to be ISO9001 certified, but probably not all management reviews are done effectively. So what shall the organization do to make the management review effective? This question can actually be divided into several questions as shown below. Let’s take a look one by one.

1.       Who shall attend the management review?

Management review must be attended by the top management team who has the authority to make the decisions about what shall be done next and what resources will be provided, because these decisions are the full purpose of doing management review. If the decision makers are not present in the management review, it will just end up in vain.

2.       How often and when shall the management review be conducted?

I have seen organizations have the so-called management review meeting once a year. If this is how often your organization does the management review, I dare say that the only purpose you do the management review is to have something to show to the external auditors from the certification body. In a real organization with good management, it must have regular manager meetings, normally held much often than once a year (probably once a month or even more often). In these meetings, the top management review how well the organization runs and what each department has done in the past period and also decide what shall be done next. So these meetings have already fulfilled the requirements of ISO9001 about management review, and they are management reviews! There is no need for the organization to have a separate meeting, with the designated name of “management review meeting”.

When determining the time and how often to have the manager meetings, one needs to consider following factors:

1)       When are the organization’s objectives set?

It is always needed to review the performance in the past to set up the new objectives. So before setting up a new target, it is desired to have a manager meeting. For example, if an organization sets up their objectives annually, then at the beginning of each year, a manager review must be held to review the performance in the past year, and then discuss and decide what new objectives should be set.

2)       How often is the achievement of the objectives reviewed?

After the establishment of objectives, manager meetings should be regularly held in order to review the achievement of these objectives up to this point. For example, an organization has set up some annual targets, and it has been decided that these targets shall be reviewed monthly to monitor their actual performance and to see whether additional actions or resources needed to support their achievement. In this case, manager meetings shall be held monthly.

3)       Are there any special event which needs support and decision from top management? 

In some cases, such as significant organizational changes, critical customer claims and legal issues, the awareness by the top management team is needed and resource is required for countermeasures to deal with these issues, manager meetings shall also be held to discuss the countermeasures and get the approval from the top management for resource needed.

3.       What shall be reviewed in the manager meetings?

In Clause 9.3.2 of ISO9001:2015, it is specified what shall be reviewed in the manager meetings (the input of the management review). It is a long list. To summarize, they can be divided into two categories:

A.       What are the objectives? What have been done to achieve the objectives? Have the objectives been achieved? If not, why and what corrective actions will be taken?

B.       What will be done next?

Let’s link the above three items with the input requirements for the management review in 9.3.2.

Input for Management Review as Specified in 9.3.2		Category	Note
a)        the status of actions from previous management reviews		A
b)       changes in external and internal issues that are relevant to the quality management system		A & B	Here the changes in the organization shall be reviewed, and actions taken or to be taken to response the changes shall be presented or proposed respectively. Decisions shall be made in the meeting on the proposed actions whether they are approved, as the output of the meeting. If they are approved, the needed resources shall be provided by the top management.
c)        information on the performance and effectiveness of the quality management system, including trends in	1)       customer satisfaction and feedback from relevant interested parties	A	Here the achievement of the objectives in the past can be reviewed. If the objectives are not achieved, root cause analysis shall be done, and countermeasures shall be proposed. Decisions shall be made in the meetings whether these countermeasures are approved, as the output of the meeting. If they are approved, the needed resources shall be provided by the top management.
	2)       the extent to which quality objectives have been met	A
	3)       process performance and conformity of products and services	A
	4)       nonconformities and corrective actions	A
	5)       monitoring and measurement results	A
	6)       audit results	A
	7)       the performance of external providers	A
d)       the adequacy of resources		A	In the root cause analysis for the underachieved objectives and ineffective actions, it can be discussed whether the resources provided is adequate or note.
e)       the effectiveness of actions taken to address risk		A
f)        opportunities for improvement.		B	More challenging objectives may be set if the previous objectives were achieved, meanwhile actions shall be proposed to ensure the achievement of new objectives. Decisions shall be made in the meeting whether the new objectives and corresponding actions are approved, as the output of the meeting. If the actions are approved, the needed resources shall be provided by the top management.

4.       There must be output from the management review and they should be followed up until they’re closed.

Any management review is meaningless without output. The actions to be taken in the future, either as correction for underachieving targets, or as improvement for achieved targets, or as the response to the changes, must be decided as noted in the above table. The resources shall be allocated by the top management accordingly for the approved actions. These actions shall be followed up until they are properly closed. 

How to Do Employees Training to Fulfill the Requirements of ISO9001:2015

      Clause 7.2 outlines the requirements of ISO9001:2015 in employees training. To fulfill the requirements, the training process shall be conducted in the following sequence:

1. Define each post and their duties

      An organization should have clearly defined job posts and the duties that the employees need to perform on these posts. 

2. Determine the competency needed for each post according to its duties, and determine the way to evaluate the competency

      The competency needed for each post is determined by its duties. For each duty the post needs to perform, there must be corresponding competency available. Also, there must be a evaluation method to determine whether the competency is really gained. A table can be established for each post as shown below:

3. Determine the competency and training needed for an employee according to posts he/she is assigned to

      An employee can be assigned to only one or multiple posts. If he’s on multiple posts, he/she must have the competency to perform the duties of all these posts. Accordingly training should be provided to meet the competency needs of all these post. 

5. Set up a training plan according to the training needs

      After the training needs are identified for all employees of the organization, a training plan of the company can be set up.

6. Conduct the training as planned

      Training shall be conducted according to the training plan, so that all the employees can obtain the competency needed to perform his/her duties.

7. Evaluate the competency of the employees after the training

      It must be ensured that the competency is gained by the employee after the training so that he/she can perform his/her duty as required. Usually, exams all required for the employees after the training. Only if the employee passes all the exams, he/she is qualified for his/her post and he/she can perform his/her duty on this post individually.

8. Evaluate the effectiveness of the training

      The effectiveness of the training shall be assessed. This can be done in multiple ways. For example, a survey can be done on the employees to evaluate the trainer, training materials or training facilities. Quality objectives can also be set for the employees. If the quality objectives are met, it means the training provided to the employees are effective.

9. Keep all the above records

      It is important to remember that whenever an employee is assigned to a new post or transferred to a new post, the above Steps 2-8 shall be repeated again. 

      It is also suggested that re-training and re-evaluation shall be provided to an employee if he/she is away from his/her posts for a long time (e.g. an employee is transferred from Post A to Post B, and then transferred back to Post A after half a year) to ensure he/she is still able to perform his/her job.

      It is also often desired that regular re-training and re-evaluation (e.g. once a year) are performed, even if an employee never leaves his/her post, to refresh his/her memory.

      Whenever the duties of a post is changed (e.g. additional duties are assigned to a post), or the skills required is changed (e.g. a manual machine is replaced by an automated one, or a work instruction is updated with new requirements), the training needs shall be identified again, and Steps 3-8 shall be performed again.  

      It is suggested to keep one file for each employee's training records. The records can contain a master list like below. All the relevant records, such as the evaluation records can be attached to this master list. With such a file, the training records of any employee has good readability, so whenever someone wants to see whether an employee is qualified, or to see what other training he/she needs, there will be no confusion.

      Finally, it's highly recommended to each organization to have a office automation system for training management. With paper records, it can become tedious and messy when the employees number goes up. 

How to Do Supplier Management as Required in ISO9001:2015

      Clause 8.4 of ISO9001:2015 requires control over external service providers. In this article, all the external service providers will just be called suppliers, a term which is more familiar to most people.

      One organization may have hundreds or even thousands of suppliers, but not all suppliers should be controlled to fulfill the requirements of ISO9001:2015. Only three types of suppliers shall be controlled as stated in Clause 8.4.1 of ISO9001:2015:

1. Suppliers whose products and services are intended for incorporation into the organization’s own products and services. Raw material suppliers belong to this type.
2. Suppliers whose products and services are provided directly to the customer(s) on behalf of the organization.
3. Suppliers by which a process, or part of a process, is provided as a result of a decision by the organization. Logistic service providers, calibration institution and subcontractors who are responsible for some steps of the manufacturing process of the organization's products belong to this type.

      Now let's discuss what shall be done to fulfill the requirements of ISO9001:2015 in supplier management. 

      First, a criteria to evaluate and select the suppliers shall be established. Only suppliers which meet these criteria can be qualified as the organization's suppliers. An approved vendors list (AVL) can be established for these qualified suppliers. All purchasing orders should only be issued to suppliers in this list. The criteria to evaluate a supplier may include but are not limited to:

• Whether the supplier meets all the legal requirements;
• Whether the supplier has the ISO certificates (An on site audit can be conducted to see whether the supplier has a solid quality management system established);
• Whether the supplier's price for the products is competitive;
• Whether the supplier's product specifications meet the requirements (If necessary, samples may be requested from the suppliers for evaluation);

      Second, the performance of these qualified suppliers shall be monitored. It is often monitored according to four aspects: quality, delivery, cost and support. A scoring criteria is usually needed so that the supplier's performance can be objectively determined. Based on their performance, the suppliers shall be re-evaluated, and proper actions shall arise from the re-evaluation. For example, corrective actions can be requested from suppliers, or the suppliers shall be removed from AVL if their performance continuously miss the target and business should be suspended with them.  

      Third, the requirements of the organization shall be passed to the suppliers. These requirements may include but are not limited to:

• Requirements for the products or service provided;
• Approval of the products and service; 
• Communication requirements (i.e. the contact window, language requirements for communication);
• Quality objectives to the suppliers, the criteria to monitor their performance and the actual performance of the suppliers. 

      At last, I want to add one point here which is not a specified requirement in ISO9001:2015, but often required by customers: the organization shall have multiple suppliers for each kind of material to ensure the continuity in the supply chain. It should be part of the contingency plan or risk management of the organization, to address the risk of materials shortage.