Ad Hoc Maintenance

Isn't this is a contradicion in terms?!

To me 'ad hoc' means 'as necessary', 'specific to the need or purpose'... this is the opposite of planned routine maintenance?

Sorry if I've got the wrong end of the stick here....it's not meant to be a flippant comment.

Del

Breakdown maintenance is just that. It breaks, so it gets fixed. It's at the 'bottom end'. It's akin to fire fighting.

Planned preventative maintenance is about inspecting, testing and monitoring the condition of things so that the chances of its breaking down are very low. It's the 'top end'. It's akin to fire prevention.

Developing a maintenance plan is so specific that it can only be done local to where it is to be carried out.

• What is the breakdown history of this piece of equipment?
• What would be the practical consequence of this piece of equipment breaking down?
• What is the lead time between the equipment breaking down and its being available for use again? What could be done to shorten that time?
• What are the commercial risks of this piece of equipment breaking down for that period of time?
• How much effort is it worth spending to prevent that from happening?

Multiply by the number of pieces of equipment at the factory in question.

Ad hoc maintenance is unorganized by nature. The only maintenance that is done is to repair what has broken. The trouble with this is that you are waiting until something breaks before doing anything. This means that the machine chooses when to stop not you. The rule in this situation is that the machine will usually break down at the worst possible time for you. A time when the costs for repair a high, such as on weekends or holidays. The other thing to keep in mind is the costs of the machine not working. When the factory is shut down because of a machine, the factory is not making money. You should add the value of the 'lost production' to the cost of the repair. I use the term "opportunity cost" because you are loosing the opportunity to produce. (The term is normally used in economics for a similar type of costing). The opportunity cost and the actual cost together will tell you just how expensive the breakdown is. Usually this amount is a lot higher the expected, but it is a real cost that effects the annual production costs. You will find that it is best to arrange the factory maintenance so that you choose when the machine shuts down not the machine. Then you can arrange "controlled shut downs". This way you can greatly reduce the amount of time the factory is shut down, and you can repair several pieces of equipment at the same time. When you plan the maintenance you can have all the spare parts in hand ready to go, and you have time to consult equipment manuals or the manufacture to figure out how to make the repairs before hand. The key is to know what is going to break next, so (to answer the second part of your question) you need to build your maintenance plan.

The first place I would start is getting a list of all the equipment in the factory, include the make model and serial number along with any other information available that you can get for each piece of equipment.

Then contact the manufacturer on each equipment or consult the owners manual if available (you should get these if you don't have them) They can tell you what repairs should be done after so many hours of operation. (example: Change filters after 250 hours, change oil after 2000 hours, Re adjust valves after 5000 hours, etc.) If the manufacture can not help you predict breakdowns then you need to increase your inspection. You will need to take every possible opportunity to inspect the equipment so you can measure the amount of wear on a machine for a given amount of time in operation. By keeping track of the wear and breakdowns in time you can predict how long certain parts last.

The next step is to keep track of the hours the equipment is in operation. For electrical equipment you can get hour counters that are installed in to the starter box. Other then that you need to keep a log of when the equipment is started and shut down.

Depending on how much equipment you have this can get really complicated to match up the counted hours and the required maintenance, so you might want to look into a software program for this. These programs can get extremely expensive. The alternative is to make a spreadsheet to help keep track but how you do this is up to you. I need more info on the complexity of the factory to advise on that. This program, spreadsheet, or sheets of paper will develop into your maintenance plan. By keeping track of the hours and checking your plan, you can determine what you need to do the next chance you have to shut the factory down.

If the factory has been working on a ad hoc basis for a long time you really don't know the state of the equipment, and you will still have unscheduled breakdowns but in time the factory will start falling in line with the maintenance plan.

One of the largest problems with a planed maintenance program is that you usually need to convince someone that they need to pay for the repairs on a machine that to them is working perfectly fine. If you run into this just go back to the opportunity cost and explain the benefits of you yourself choosing when the equipment shuts down. Over time the costs of operation will be reduced by a great deal.

Hope this helps!

If you do, or your management team tends to wait for things to breat down, you might want to goto www.unconventionalsolutions.biz to see how Thortex Engineering Solutions can minimize the down time and maximize you up time. DK

Thank a lot for your helps.

It means "preventive maintenance", doesn't it?

Best regard.

Effective "preventive maintenance" is the goal and the best way to reduce down time of the factory.

Hi nam70,

I have worked as a field engineer on printing machines most of my working life and have seen the full spectrum of maintenance and the lack of it.

If you do NOT introduce a preventative scheme on set intervals, you will without doubt suffer higher costs in the end for breakdown maintenance is always resulting in UNPLANNED production stoppage. This means that work will have to be sent out to be done on time as you hardly ever have overcapacity.

The thing is that when your bosses decide NOT to do any maintenance, they will not see the cost of this untill some time later at which time the problem is not so easily correlated to that decision. In other words if you are the maintenance engineer responsible for the plant, you will get the stick for all those breakdowns as in their words, you did not do your job right.

It is either preventative maintenance or nothing. Ad hoc should just fill the gaps for those unforseen events that WILL happen.

Good morning Nam70: The answers you received were right on target. PWSlack and KWNish gave you excellent summaries of why Preventive or now sometimes refferred to as Predictive maintenance is the key to an effective program. I would add that it is not all that expensive now. I've been working with facility managers to develop just such a system to address the issues described. A small US company called Condition Maintenance has a program called TFM for Total Facility Maintenance that does exactly what PWSlack and KWNish suggest. It is new, and is now in use at several major companies in New Jersey in the US. TFM uses another new system called BearingLifeGuard which provides exactly the information described in their responses on machines with rolling element bearings. You can check that system out at www.Bearinglifeguard.com and on Global Spec. Both systems provide the capabilty described by your respondents. I don't know if TFM has a web site but I will check and let you know. VIBES

Hello again Nam70: Regarding TFM (Total Facility Maintenance) that I mentioned earlier. Condition Monitoring, LLC is a small engineering services firm in Morris Plains, New Jersey. They have been developing and implementing this program over the last four years. (...or more.) The owner was formerly a facility manager so he understands the problem. I believe they offer a software-Do it yourself.- package for the program but I'm not sure. If you want more information on their system/Service, contact the President James Meeker at MEEKERJH@OPTONLINE.net. I've seen it in action and it is quite impressive as a supervisory/management organizational tool. I was helping with the bearing analysis portion. Their program basically reduces all of the complex factors to metrics that can be easily tracked and provides exactly the information suggested by PWSlack and KWNish. Good luck. Vibes

In addition to the comments below:

One of the major components to maintenance is proper lubrication. Though manufacturers have specified recommended oil change intervals, they can usually be extended to 2-4 times this recommendation. The way to do this is with oil analysis, a system for monitoring, and a premium lubricant such as Schaeffer Oil (216-401-1845). Schaeffer's lubricanill typically run 20% cooler than the major oil companies, reduce amp draw by 5%, and extend oil drain intervals with less wear.

YOURS NOW FOR THE LOW LOW PRICE OF $19.95!!! + S&H

Seriously what theoilguy is saying is true. Don't just settle for a low grade cheap oil to lubricate your machines. I always make sure I use what is recommended by the manufacturer or higher grade(typically I use the highest grade lubricant available).

I have been at this for 25 years and I find that the more expensive lubricants may be just that up front but in the long run actually come out to be cheaper.

Just don't forget that you can do things to your electrical to maintain it as well.

Every year, each machine in my shop is shut down completely power is disconnected and all electrical connections are checked and tightened. Most maintenance programs forget this. Electricity in the US vibrates at 60Hz the same frequency as the supply voltage. this vibration over time loosens connections, and if you have ever dealt with loose connections in the past you know they generate heat due to the excessive load created by them.

Loose connection = higher current draw = more heat = fried wiring

Just a bit of input from past expierences....(Yes this has happened to me)

You can't possibly plan for ad hoc jobs: they're done as and when required. What you can do is plan a scheduled maintenance program based upon the machine manufacturers' recommendations so as to minimize disruptions & breakdowns.