Shop Efficiency - Part 8 : Gauging Your Shop Efficiency with the Magnificent Seven

We have dedicated a lot of time and brought out a lot of ideas in our Shop Efficiency series ... but most have been based "on the shop floor" and have targeted machining ... set-up ... and tooling. Quite a few clients have written us to ask about the business side ... more of the "How do I actually know if my shop is efficient" ... which is a great question. So in this post we turn our attention to the shop management and specifically ways of gauging your shop efficiency.

I have listed a few of what I consider critical areas in this Shop Efficiency post ... one's that I feel are among the easiest to gauge and important to watch ... what I call the Magnificent Seven. The points below are not in the order of most importance ... just simply a list of all the metrics. Creating a spreadsheet and taking a daily count with most of these factors will allow you to see the results as they happen ... and over time will reveal the ups and downs of the shop in general ... and allow you to make corrections. You can start your journey on the first of the month ... for example ... and take a few minutes every day or every week to fill in the numbers ... building the information in the spreadsheet as you go along. Make a graph ... and watch what these factors will reveal. If you stick with it ... you will be shocked ... maybe happily ... maybe not.

(1) Revenue Per Man Hour
Revenue per Man-hour is the annual revenue ( or do it by month ) divided by the total paid man-hours, including paid vacations and overtime. Keeping a running total of these activities and although this is a general look at the numbers ... it can be very telling.

(2) Lead Time
Customer Order Lead Time includes order-entry through production to shipment for every job. Again, start a running list from the first of the month and carry on. This stat will reveal your shop efficiency as well as give you a chance to look at the quantity of work going through the shop ... and the time frame it takes to go from order received to revenue received.

(3) Labor Turnover
Labor Turnover Rate is the number of voluntary and involuntary separations divided by the typical

number of employees. Hopefully you won't be keeping a monthly log of this stat ... but keeping a log of the turnover rate will still yield a telling tale. Although this stat has it's own revelation ... it also shows one key point regarding efficiency. When an employee leaves a company ( for any reason ) he / she also takes a piece of that company's memory and experiences with them. That loss of memory or experience can lead to efficiency and productivity loss. A company that experiences high turnover rates needs to find ways to insure that experiences and memory don't leave the building along with the employee. A low labor turnover rate ... as the inverse ... helps achieve and maintain high performance, productivity and efficiency.

(4) Completion Rate
This factor can be described as the On-Time Completion Rate. It is the percentage of goods delivered on time. This is ... obviously ... a direct result of shop efficiency. Keep a log for every job going through the shop and how it fared in the On-Time Completion Rate.

(5) Scrap and Rework
This factor is the Scrap and Rework as a percentage of shop sales. Scrap and rework cost time and

money. Some scrap and even some rework is inevitable ... but this factor may be most useful as an indicator of how well things are going out on the shop floor. An high scrap and rework percentage is an early tip-off that something ... or someone ... needs a deeper look.

(6) Machine Uptime
Total Machine Uptime is the hours of production as a percentage of the total operating hours for the shop per week. In other words, what percentage of an average shift are each of your shop's machines running. Basically put ... your employees get paid every day whether they are productive or not ... idle machines are not making that money even though the employees are getting paid. Therefore, how much a machine is up and running becomes an important factor for determining just how productive and profitable that shop is.

(7) Machine Availability
Machine Availability is the time machines are actually available for use compared to the time they are supposed to be available. Unscheduled maintenance or other problems will reduce a machine's expected availability ... and impact production schedules negatively which in turn reduce the ability of a shop to deliver product on time.

There will be some out there that utter the phrase "I know all this just by being out in the shop every day." And that may be true. But seeing the numbers on "paper" ( it might be your computer screen ) is much more telling ... and much more emphatic ... and makes the point much more clearer.

So ... there you have it ... the Magnificent Seven. Keeping a close eye on these factors or metrics will most definitely put your shop's efficiency in glaring focus ... and will most likely open your eyes and mind to whole list of other metrics that may be pertinent to your particular shop and operation. Taking the time to develop and review your information as it develops will prove to be more than worth the effort ... and keeping the faith will insure your shop is on the straight and steady track.

Please come back for our next installment in our series on Shop Efficiency.

Until next time ... Happy Chip Making !!

At Kentech Inc. we are MACHINISTS who create Real World Machine Shop Software.

Who creates the machine shop software guiding your shop's future ??
Check out all our REAL WORLD CNC & MACHINE SHOP titles at 

www.KentechInc.com

Shop Efficiency Part 7 - CNC Programming

Our Shop Efficiency series has really taken off ... and we would like to take a few lines to say Thank You to all our readers for your email comments and support. We are very pleased that we have been able to take some of our real world machining and machine shop experiences and turn them into valuable tips and pointers and pass them on to so many of you. Thanks so much for your support.

First - A little background on this Post
At first glance ... since Kentech Inc. develops and sells CNC programming software ... this post might look like straight marketing and a sales pitch for our Kipware® conversational CNC programming software. Actually ... it's a story of just the opposite. Most of our software titles have been designed and developed based on what we saw was lacking in our many years on the shop floor. Our Kipware® conversational CNC programming software is a product of that experience.

One of my most telling personal experiences was working in a shop here in Masachusetts as a CNC machinist. The shop was your typical job shop with all kinds of work coming through the door. Most of it was fairly simple ... with a few plastic injection mold type jobs every once in a while. The CNC programming was supposed to be done by the shop floor machinists ... using a CAM plug-in for Solidworks ... which was a bit complex. No CAD/CAM training more than a simple tutorial was offered or provided. As a result ... since most shop floor machinists were great at cutting chips but lacked intense CAD/CAM experience ... and the jobs were fairly simple ... they often resorted to manual programming. The result was programs loaded with mistakes ... from typo-errors to incorrect toolpaths ... and the result from that was scrap, broken tools and sometimes worse ... but the overall effect was complete shop floor inefficiency.

The frustration level on the floor ... needless to say ... was very high. The machinists were basically unable to do their job ... because no one trained them on the complex CAD/CAM system ... and there were no other tools to help them ... other than an editor.

In this environment ... our conversational CNC programming concept and design was born. It was plain to see that the CAD/CAM and a CAD/CAM programmer was required for the mold work ... but clearly for the 95% of programming we did on the shop floor it was NOT required. In fact ... having the CAD/CAM option as the only option ... actually made things worse.

CNC Programming and the LINK to Shop Efficiency
Which brings us to this post and the subject of CNC programming as it pertains to shop efficiency. Obviously ... if the program isn't created in an efficient and correct manner ... the parts don't get made and the money doesn't flow. But just as important as tooling and fixturing ... the program creation process must have options also. You wouldn't think of placing a simple rectangular piece of stock in a custom made fixture ... you would use a vise. In the same way ... you shouldn't think of programming a simple part with a round pocket and bolt circle through a complex CAD/CAM system. The real key to efficient shop floor programming is having an ARSENAL of tools at your disposal. Thinking about your CNC programming as more of a tool ... with multiple choices for various situations ... will help your shop floor reach a higher level of efficiency.

CNC Programming Tools Available
We've listed what we consider to be the realistic options for CNC programming available to anyone creating CNC programs in a "job shop" environment ... the environment where our readers predominately are working ... and the options up for discussion in this post.

1. CAD/CAM
2. Off-Line Conversational CNC Programming Software
3. Conversational CNC Controls
4. G Code "wizards"
5. Manual Programming through an Editor

"Wizards" and Manual Programming
To narrow the discussion a bit ... let's remove the two options that are really not realistic in a professional machine shop environment. So called G code wizards are way too simplistic and act

more as hindrance and weight than any kind of efficient tool. Full conversational programming software makes much more sense both from a financial and capabilities perspective. Full, quality conversational software is a programming system ... not a simplistic crutch.

Manual G code programming should only be considered for the simplest of parts. Human error plays too great of a role in any other scenario and really renders this option a last resort choice for a professional programming environment.

That's not to minimize manual CNC programming knowledge and experience. Any CNC programming option used is made VASTLY more efficient and productive when operated through the hands of an experienced manual CNC programmer. A good Editor should always be available to allow that experienced CNC programmer the tool to alter or edit auto-created G code. The point here is that creating programs from scratch manually is not a good choice. Even for simpler programming ... a tool that will auto-generate the code provides stability ... and the manual tweaking of the code can enhance that output greatly.

CONVERSATIONAL and CAD/CAM
Efficient CNC Programming Requires an ARSENAL of Tools
It's more about OPTIONS than OPTION
In a professional environment ... really the two main options are CAD and / or CAM and full, quality conversational programming software. The CAD/CAM option can really be broken down into two options. First the CAD option is a must for any design environment ... even when that is just supporting the shop floor with fixture design. Professional CAD can range from the simple to the complex ... and from the FREE to megabucks. Each shops design and CAD needs would drive that discussion. However ... going from the CAD drawing to a G code program does not necessarily have to through the expensive and complete CAD/CAM system.

Using conversational software ... that CAD drawing can also be turned into a G code program. DXF import can be used in quality conversational software and a variety of other applications to go from a CAD drawing to a G code program.  And of course ... the integrated CAM option can be used to go from that CAD drawing to a G code program.

The main point is that no two workpieces are exactly alike ... and the right programming option for one will most likely not be the right programming option for another. From our experiences ... the best programming method for any job involves (2) main factors :

• Who is the best choice to create that program? Shop floor? Dedicated programmer?
• What is the best tool for that individual to use to create that program quickly and accurately?

Letting the correct answers to these questions guide the process ... rather than forcing the path because of limited options ... will increase your shop efficiency when it comes to programming your CNC's. Some thoughts :

• Maybe the best person to create the program is not full CAD/CAM proficient but would be the best chip-maker for the job ... a shop floor conversational programming option might be the best solution. 
• Perhaps the job is very complex ... and the only solution for an accurate and efficient toolpath is the CAD/CAM alternative. 

The point to make is that with an arsenal of tools available ... the experience of your personnel and the complexity of the workpiece / programming can dictate the most efficient path to take for the program creation. This allows for the free flow of efficiency ... rather than ramming the square process through a round hole.

Machine Tools with conversational CNC controls
Conversational CNC controls mounted directly to a CNC machine appear to be the perfect solution ... but actually have some important points to consider. The alternative of purchasing a laptop or Windows based tablet ... loading it with conversational software ... is more often than not the better alternative. Here are our major reasons to support this claim :

1. CHEAPER ... conversational CNC controls can be quite expensive. A tablet with conversational software will cost less than $1200.
2. PORTABILITY ... having the ability to do the programming on the shop floor, in the office, at home ... makes a portable alternative very attractive.
3. PROGRAM MULTIPLE MACHINES ... the ability to simply move the laptop around or pass it off to someone else gives you the ability to use the "conversational control" on multiple machines. Other machines can also be purchased without the conversational option ... you already have a "conversational control".
4. PROGRAMMING AT THE MACHINE ... even though most modern conversational controls have basically (2) modes ... the conversational programming mode and the machine operation mode ... they can often result in headaches and frustration. Either the machine is not runnning waiting for a program to be created ... or the machinist is programming the next job while trying to run production. Not the best environment to say the least.
5. CNC CONTROLS ARE NOT COMPUTERS ... most industrial grade CNC controls do not have the power or capability of a desktop or laptop PC ... they are simply not constructed from the same components. And if they are a PC ... they are most likely NOT an industrial grade PC and not fit for the harsh machine shop environment.
6. CONVERSATIONAL SOFTWARE IS MORE POWERFUL ... backed by the power and capabilities of a PC ... conversational SOFTWARE is more powerful and has more options than conversational software operating on a CNC control.

Some Closing Thoughts ... 
The main reason for combining this post into our Shop Efficiency series is to get shops thinking about all the potential programming tools available. Our experience shows that the most efficient CNC programming is accomplished when an ARSENAL of good tools are made available. Inevitably users might find and use their favorite tools ... but the key is that they have the ability to choose from an assortment. Also ... that the other tools remain available when the need arises ... providing choices. Also ... when an assortment of tools is available ... shops can increase the number of people who can create those programs ... and that is a huge jump in shop efficiency. Creating CNC programs faster ... using more people ... means more spindles turning and that means more profits being generated. And isn't that the true test of Shop Efficiency?

Please come back for our next installment in our series on Shop Efficiency.

Until next time ... Happy Chip Making !!

At Kentech Inc. we are MACHINISTS who create Real World Machine Shop Software.

Who creates the machine shop software guiding your shop's future ??
Check out all our REAL WORLD CNC & MACHINE SHOP titles at 

www.KentechInc.com