 Hello friends. Today we will discuss about critical examination phase of the method study. The outcome of the session will be, you should be able to apply the knowledge and purpose and means in the critical examination to the problems. The content will be, what is critical examination? What is the procedure for it? And what are primary questions and what are secondary questions? At the end of this, we will be able to apply these questions and then find out a better alternative method for the existing, existing method of doing the job. Critical examination, each element of the work as presently being done and recorded on the chart is subjected to a systematic and progressive series of questions with the purpose of determining two reasons for which it is done. If you just recollect what are the various stages of the method study is, select the job, then record the various facts after selection and recording. The third stage is critical examination. Now the meaning of critical examination is this particular stage will tell us what is being happening in the current situation and the current present method. What are the possible alternatives for the method? And this is a typically systematic way of going for the questions and then definitely we will be able to arrive at a better and alternative method. Based on the reasons, improvements are found and adopted into a new method called a better method. The examination thus requires exhaustive collaboration with everyone whose contribution can prove useful and also full use of available resources of technical information. What is the procedure for critical examination? The use of questioning technique reduces the possibility of missing any information which may be useful for the development of better method. It is always said that asking question is more difficult than giving right answer. If you ask a vague question, you are bound to get a vague answer. If you get a specific question, naturally you will get a specific answer. So based on the focus based on the target of the method study, we should develop an attitude of asking the right questions at right time and that should have a typical flow for the questions and a typical technique for the questions. There should be a procedure for this, a popular procedure for carrying out critical examination is using two sets of questions. The first set is generally called as primary question and the second is called as secondary question. Primary questions are those questions where the answers to these show up the necessity of carrying out the work activity. What is the necessity is that work was really necessary, is that activity is really necessary and then you should have to find out whether this is required or not. And then secondary question which allows consideration to alternative methods of doing the activity. This is the most important part of the critical examination where secondary questions asked in the right manner and observed very closely to the facts will definitely come with lot of alternatives for the present method. So primary secondary questions together will help us to find out what are the alternative methods. Now primary question, the first one purpose, the need of carrying out the activity is challenged by the question what is achieved? Is it necessary and why? To answer these questions determine whether the particular activity will be included in the proposal of any method for the process. For example, if a machining process is being carried out on any machine for example lathe machine or CNC machine or VMC machine and then we are supposed to make some method study on the machining process. After collecting the data after analyzing with the various parts of recording techniques when we come to the critical examination, the first and foremost question what will come to our mind is what is being done? And what is being done? Why it is being done? Suppose the answer is machining is being done, why the machining is being done? Since the answer can be machining is done only to meet the drawing requirement, sometimes machining is unnecessarily done because foundry processes are unable to get the machined surface required. I have seen many such cases where there is no requirement of the machining process on the castings but whereas practically it is done because the foundry is not capable of being producing the surface finish and the tolerance which is required. Many times in the machining process also we are confused with machining surface finish and tolerances. Sometimes the drawing suggests that better tolerance is required, machining surface may not be much important. Whereas in some other cases surface finishes of high importance tolerance may not be important. In both the cases we are confused directly write what is being done, machining is being done. What is the accuracy involved and what is finish required in that is generally becomes a secondary consideration. Therefore, the primary question about the purpose is it will tell you what is being done and why it is being done. The means, the second question in the list is the means of carrying out the activity are challenged by the questions how is it done and why that way only. After what is done and why is it done. The next two questions are how and why how the machining is done. Now machining is done sometimes since I got a machine which is available. I am using that machine for the utilization purpose and I am using that particular machine. In fact, the capability studies and the drawing requirement is not really calling for that such a high resource machine. Even I can do the job on a lathe machine but whereas I don't have a lathe machine capacity it is being used for roughing and at the same time I see CNC machine being idle so naturally I am tempted to load the job on the CNC machine. How it is done it is done as per the process sheet we are basically have to challenge it and why that way only why CNC why lathe why drilling so on and so forth. We able to find out the particular questions in that direction we are getting the answers in similar manner. Definitely this particular stage of means we should be able to answer how is it done and why it is done that way only. Once these two primary questions are finished we are moving to the secondary question of the same two questions. The aim of the secondary question is to arrive at a suitable alternative to the presently used method. At the end of the secondary question one must get various alternatives as an answer for the secondary questions. For example, if you take the same purpose if the answer to the primary question is activity necessary is convincingly yes then alternatives to be achieved the objective carrying out and the activity are considered by the question what else can be done. For example, we have thought that machining is done why is it done is it done to achieve the requirement of the drawing. Now if it is really necessary we have to say the yes in many cases it may not be necessary we can directly avoid the machining process itself there is no question of alternatives we can directly come to the conclusion yes it is not at all required probably we can eliminate the entire machining process which was being carried out. If the answer says yes yes machining is required then what else can be done whether the same machine is required the same process is required same tool is required same speed field required whether the same sequence is necessary whether the same operator and the skill level of the operator is necessary and so on and so forth what else could be done we will have to have lot of alternatives for what else can be done. For example, in a CNC machine we can have there can be some operations wherein as I said lathe machine may be sufficient but we are using CNC because of some other considerations or because of a stray instance where on some day we receive a stray complaint that the lathe machine is not capable and as a result of that we are trying to shift it into the CNC machine. In fact the answer would have been why the lathe machine is not giving the required accuracy probably maintenance of lathe machine can help us and then we can shift the job from CNC to lathe machine once again what else could be done definitely we will have lot of alternatives for this particular situation. Means all the alternative means to achieve the objective are considered by the question how else could it be done. Matlab when we are considering the various options we need to have how else how was done that was the primary question how else it can be done that's come the secondary question. In the purpose what else could be done now in the secondary question of the means while saying that how else it can be done how else that can refer to maybe in the tooling related jobs maybe in the fixture related job or maybe we can combine some other operations we can eliminate the operations we can reduce the time required for the particular process by way of finding out the better method with the help of a better means. The means may be related to the man may be related to the machine or may be related to the equipment or tooling and so on. It can also be in case of metrology for example we are checking a particular dimension we are checking with the help of a veneer caliper or micrometer or a dial indicator and since it is a age old process we are continuing it how else can I measure it can be possible with a plane go gauge snap gauge or ring gauge or a plug gauge where it can definitely reduce the time since we establish the process we definitely can think of this below shows a sample sheet for use critical examination is done what is the achieved is it necessary yes no what else could be done and in case of means how is it done why it is on that way only how else it can be done so these are the possible summary of the purpose and means of the primary and secondary questions now we have to think of a situation where a manager has started to manufacture the job with the help of CNC machine initially the same job was used to be produced on the lathe machine just to get CNC machine engaged and whose drawing shows no dimensions are critical and is this manager's decision right or wrong it can be improved it does in the plain thing whether a CNC job is really necessary the job is really calling for a CNC machine or not to think on this the answer obviously is no manager decision is not correct the best example for the means is very in the critical examination of the method definitely initially the same job was done on a lathe machine and since the company purchased a CNC the manager shifted the CNC the job on the CNC machine with some additional other considerations okay thank you