Transcript

Welcome to the fifth lecture in Week-2, for this course. We have discussed about the characteristic of the product, we have discussed about the purposeful or functional characteristics, the operational characteristics, aesthetics price to customer. I will cover the last and very important characteristics that is designed for Maintainability or Ease of Maintenance. In this I like to start with that the selection of material and class of workmanship is closely related to two factors – design of the product and economic and analysis of its cost. This is discussed the cost is discussed in the previous lecture and quality is not an attribute to define the two responsible factors are Durability and Dependability.

Dependability is the reliability or the robustness with which the product is designed. Durability ends upon the maintainability or the ease of maintenance for which we have designed the product. The length of service life or endurance of the product is defined as durability, this is the Definition. Maintenance and repair are the aspects of durability. The preventive maintenance and requisite repair required for some product is closely back into quality and design policy. Preventive maintenance an important term is there. Like preventive maintenance the other maintenance that I will just start discussing productive maintenance, corrective maintenance, breakdown Maintenance. What are these maintenance, let us see. There are different types of maintenance that agriculturists use to increase the availability of their Machinery. By availability I mean to say the productive availability time for which the machine should be able to work at the peak performance, that is very Important. So based upon the farmers budget and the amount of resources, level of combined experience and maintenance goals one or more maintenance types are Used. Number one is Preventive Maintenance, number two is predictive maintenance (Condition monitoring) also comes in the predictive maintenance, number three is corrective maintenance, number four his breakdown maintenance. The above two are known as Proactive, Proactive maintenance. The lower two are known as reactive. Why proactive? Before the failure happens we take the measure as the word preventive itself means we have some plan and we prevent the failure to happen. Preventive maintenance actually planned maintenance and we make a schedule for the maintenance for instance for the tractor you get it serviced in every three months or for depending on the usage. Of the new product that you purchase there is a service schedule for that given by the manufacturer. That is preventive maintenance. Before, anything happens based upon the schedule you just do that.

Next is Predictive Maintenance. In predictive maintenance what happens we predict something based upon that we do the maintenance before the failure happens. Various kinds of monitoring happen here for instance temperature. If you identify that your tractor that you are working on is heating much higher than the normal. If you identify that the vibrations are quite higher in the implement that you’re using. If you are identify that the knives that you are using are not working that Properly. That means it has become a little blunt. It is prediction based upon this prediction you start doing maintenance. This is known as Predictive maintenance and when we use some instruments for this-some temperature measuring instrument like parameters, some radiographic instruments, some vibration instruments like dial gauge. It is known as Condition monitoring.

Next, what is Corrective Maintenance? As I said Corrective and Breakdown maintenance are Reactive. Corrective maintenance is when some small failure has happened, Your tractor is giving some flashes, some beeps are coming from tractor okay, some jerks are there when instance your start would might have gone bad so there might be something stuck in the silencer some failure has happened then you go and get that repaired, this is corrective maintenance. But in case your machine comes to standstill the tractor completely stops then you have to do the maintenance before it starts working that is known as breakdown maintenance. So Corrective and Breakdown small introduction to them is given’ the reactive are these two and the above two are the proactive.

Let us try to see all these individually-Preventive Maintenance is the most popular type of proactive maintenance. The objective behind Preventive Maintenance is to either repair or replace components before they fail Periodic Maintenance may be done at calendar intervals after a specified number of operating cycles as I just said and or a certain number of operating hours. Those intervals are established based upon manufacturer’s recommendations because here we have the designer. So we are the manufacturer here, we are employing design thinking into agricultural implements, we need to see whether we are designing for the maintenance, or not. And when the maintenance has to happen that also has to be considered. When we were prototyping, when we are testing for in that phase also the maintenance would be checked. How about with preventive maintenance the agriculturists run the risk of over-scheduling. The maintenance tasks because tasks are scheduled based upon the time rather than actual conditions. So irrespective of the actual conditions sometimes manufacturer’s instructions are followed. So there is a little drawback for preventive maintenance app as well it is now taken with a very well care. An example that can be taken here is that the tractor that you have just purchased that has an instructor’s or manufacturers manual in which you have to get that tractor serviced after six months. But maybe you might not have used the tractor for even 100 hours so in that case that maintenance might not be required. So there’s a certain overscheduling is there. So that has to be taken care when we design the maintenance.

Next is Predictive Maintenance or Condition Monitoring. Predictive maintenance is what savvy maintenance teams aspire to have or already implementing. Major barriers to this is the time it takes to implement rather than the cost of the technology Itself. For instance a vibration sensor that can identify imbalance misalignment and resonance issues only cost rupees 5000 but time it’s takes to install, integrate with each other maintain a software and adopt a culture around is not time that all practitioners are willing to allocate. So when I talk about condition monitoring specifically it used instruments. For those instruments are implementers has to be trained. So that sometimes takes some time which many farmers are not willing to do. In Predictive maintenance as I just said temperature monitoring is there when we see that the heat is a little higher than the normal then vibration monitoring is there then oil analysis for instance or your tractor that is consuming 50 liters for the specific hector’s and now it is consuming 70 liters this is Oil Analysis. That the amount or the fuel that is consuming is quite higher or the oil the lubricant oil that you are using here is getting blackened very early, this is oil analysis. Then is Radiographic inspections you use radiographic instruments to find the radiographic waves for that. Similarly, electrical testing for the like changing the resonance, conductivity those are all technical things those can happen. Similarly, performance testing they just took the example of the tractor. If it is not performing properly all these monitoring can happen.

Next is Corrective Maintenance. Corrective maintenance is inherently part of Emergency maintenance because when there is an emergency something needs to be corrected or fixed. In this way corrective maintenance is mostly reactive. However, it can be proactive as well if an asset with condition monitoring sensor detects an issue or work order is created and a technician is sent to corrected. In this case it becomes predictive maintenance. So this is corrective maintenance. Last one is breakdown maintenance also this is known as Emergency Maintenance. This occurs when an asset requires immediate attention in order to keep a facility operational or safe. This is the most reactive and intrusive type of maintenance. As it cools technicians away from other jobs and lowers scheduled compliance. In extreme circumstances emergency maintenance can set an organization back days depending upon the scope of repair, availability of the parts and asset level of importance. To reduce the amount of emergency maintenance that is both unplanned and unscheduled organizations adopt various forms of proactive maintenance so, it is completely undesirable to have a breakdown maintenance. If build on maintenance is there that means something is wrong with our schedule or with our planning. With this I’d just like to give some tips on design for maintainability. When I’m a designing the product what should we do? Maintainability is created during the design process it cannot be added later. This is the basic mantra for design for Maintainability. Once the product is designed then you cannot inculcate maintainability into that. So while designing only the number of components you are designing the number of a sub assemblies you are having those are all to be considered considering the maintenance that you are going to implement or to use further. Establish the maintenance philosophy in terms of repair versus disposal of the product of components do this before starting any Design. Repair versus Disposal are we going to repair the components time and again or we just gonna use the component once that is one time used and then dispose it away. This has to be considered freehand. Consider where maintenance will take place first, second or third line. Regarding first, second and third line maintenance first line maintenance is when the farmer himself is able to do some maintenance on line. Like in the field only some vibration is there. He is able to screw or tighten some nuts that happens. Second line maintenance is when he has to stop the Machine and take you to the closed service center. The second service kind of thing happens so that is second line. Third line maintenance is when the complete overhaul of the machine is there , when these people took us to the further expert centre or the central point when the maintenance overall maintenance has to happen. So depending upon this level it is design. Consult the maintenance and engineer during the design phase and agree upon a set of documents to be handed over to the maintenance people. Keep it simple, very basic concept. Complex arrangements are usually harder to maintain, make it testable, reactive or fault running tests often reveal latent problems that will become false in near future. So to counter that one must include diagnostic test points in electrical circuits include mechanisms that provide early warning of impending failure. Design reliability into items that are difficult to maintain such as components, deep components within ensuring the components for which the reach is too Intricate. So that are to be designed very robust so that the maintenance for that is not required very frequently. Reduce maintenance frequency overall by ruggedizing and overspecifying components to withstand occasional overload. Provide warning labels wherever a maintenance engineer may be exposed to danger for example on hot or heavy items or any sharp items or any electrical items where electrical shock could come, so that is very important to provide symbols and logos and warnings. Provide maintenance instructions and information panels if the routine is difficult to understand or remember and fix them as close to the point of maintenance as possible. Design equipment to fail-safe so that risk of injury to maintenance engineers is reduced.

Fail-safe means providing fuse, providing emergency brakes, So that the big failure, big breakdown doesn’t happen. So that the operator is safe all the time. Avoid the requirement of special tools. The normal or standardized tools, spanners, screwdrivers, pliers should be able to work on to carry out the maintenance activities. This is also important. These were a few design tips designed for maintainability tips. With this the characteristics of a product are covered. Next, I will have a small lecture on key factors for a successful product. That is just for if you are a developing an implement to commercialize that if you want to commercialize some product you need to think about the market, you need to think about the trend in the market, you need to think about the demand, you think about the competitors, that is also important So, that I will cover a small lecture next.

Thank You.