Thursday, January 12, 2012

Dr. Who and the CAD Manager, Part 2

January 5th, 2012

Welcome back from last month. It was an exciting return trip after dropping you off. I didn’t have quite enough battery power to make it to my destination but fortunately I landed in a shopping mall outside of Miami that had those new car chargers available. I hope the Chevy Volt owner got fully charged after I surreptitiously borrowed his hookup for a while. For this month the TARDIS is fully charged so if you’re ready let’s take another trip back in time...all the way back again to 1991. Here we go.

You’ll remember I had just started up my company and began my quest to improve my AutoCAD productivity. I shared with you a scanned image of some job time logs I had manually recorded while previously employed, performing design and drafting work on a board. From these logs I created the following spreadsheet to help visualize my work effort and output. This would serve as a benchmark to measure against as I massaged my AutoCAD standards, drafting techniques, and customized AutoCAD work environment.

Manual Board Drafting

By studying the spreadsheet you will see I’ve graphed (in blue) the total job time which is the sum of layout, detail, and checking time per the sum of manufactured details and commercial components. Also graphed is the total job time (yellow), layout time (Green) and detail time (beige) per number of manufactured details. My main area of interest was the number of detail manufactured parts, primarily because that was where the more original thinking was required. Commercial parts were more quickly drawn due to having dimensional information or it was a matter of simply tracing over a template. I did not attempt to differentiate between the complexity of the detailed parts such as a weldment or a spacer plate, I was interested in establishing an average. To a certain extent that explains the peaks and the valleys as some jobs had a greater number of complex parts, some less. The end result of this exercise as you can see is a typical job required 4.72 hours to complete per manufactured detail and the average time to detail was 1.73 hours per detail. For charting, checking time was not included so you’ll notice a slight disparity in the total hours per detail part.

Starting out fresh I had much to do, selection of a computer (my first “real” one), self taught AutoCAD and AutoLISP learning, supporting software selection, printer, file cabinets and more, too many details to bore you with. The main focus was on designing and building the machine I was committed to, until that was complete the search for increased productivity was placed on the back burner. With that in mind let’s jump back into the TARDIS and dial in the year 1993.

I was pretty busy during the intervening two year period, completion of the machine design and build, additional design jobs, and many AutoLISP routines to write for tweaking my system as shown in this list:

Now I had several AutoCAD jobs under my belt to make some comparisons, although the first few jobs were not recorded. Those that were recorded would offer some insight as to how things were developing. The following spreadsheet was created in July of 1993.

AutoCAD Modeling and Drafting Benchmark

I used similar metrics as previously, however checking was no longer recorded, I abide by the old principle of measure twice - cut once and after a design was completed with numerous amounts of LIST and DIST commands checking was redundancy upon redundancy. You will also note I grouped modeling in with layout. Mind you it was not true modeling, at the time I was constructing my models as simple 3D wire frames, in fact all my construction was done with just lines, circles and arcs. I had determined that polylines were memory hogs in AutoCAD and they were more difficult and time consuming to work with. Bottom line is a typical job now required only 2.20 hours to complete per manufactured detail and my average time per detail was down to .74 hours.

The take away from this is the CAD software vendors were right - CAD is more efficient than manual drafting however I can attribute much of the productivity gains to the methods and customizations that were implemented. Specific dates are not indicated on the charts but I’m certain you can determine the point at which many of the changes took affect. Now it was time to discard the old benchmark and replace it with a more current one, one that reflected strictly AutoCAD work. It is also time to hop back into the TARDIS and make another leap forward. I’m not exactly sure how far ahead we’re going because of those missing dates on my charts. I guess we’ll have to wing it and hope for the best. OK let’s have a look around, yes it seems we are right on target although oddly I don’t see a calendar laying around. I do see another spreadsheet created a number of jobs later.

AutoCAD Benchmark Comparison

As you can see, I’ve continued to make progress on my quest. In the previous installment of DWATCM (Doctor Who and the CAD Manager) I stated “Until you know where you are currently, it will be difficult to establish goals for where you want to be.” I’m going to show you one more spreadsheet. Actually it is a scan of some charts I had made at the time. You see, I had neglected to close the file on my computer when I needed to make a slight time jump. I was not aware that Doctor Who’s nemesis Henry van Statten was nearby. Upon my return the spreadsheet was missing and I was left with only printouts I had made on my dot-matrix. There’s no telling what old Henry has in mind for those charts and he’s probably the guy responsible for the missing calendar too. Well anyway, this is it:

AutoCAD Goal Set

I’ve added some coloration so you can match the charts up but there is a little further explanation to do. First, the vertical bars are representing the trend of the particular metric measured over the accumulated individual jobs - the running average. Secondly, the upper left graph does not reflect the inclusion of commercial items - this was consistent across the AutoCAD data. Finally the lower left chart does separate the model time from the layout time, unlike the previous two charts. For this graph I plotted the static average indicator from actual data however.

The red lines overlaid on these charts are averages taken from the AutoCAD benchmark spreadsheet and the AutoCAD comparison spreadsheet. What has remained unspoken until now was that after first establishing the original AutoCAD benchmark the goal I had set for myself was to halve my times. At this point I was very close and that was when I set new benchmarks. The shorter red bars to the right were new goals based on the new benchmarks. You’ll notice they were not as aggressive as the first goal, I felt there was a law of diminishing returns that would enter the picture however I underestimated the continued gains that were possible, relentless pursuit would shatter those marks.

Do you hear that? The alarm on the TARDIS is ringing like mad. Doctor Who must be having some type of emergency and desperately needs his vehicle back. Hurry in now, we must return to the present so he may take care of his business. Ah yes, here we are, all back in one piece and it looks as though the TARDIS has retained plenty of power, The Doctor will be pleased.

To conclude these little time travels, I hope I’ve given you some insight to arm yourself for your own time travelling. There is much to be gained with a little effort and resources are available that can aid you in that quest. As you begin your travels perhaps our paths will cross and we can share a beer in some corner of the Fitzroy Tavern.

Patrick Hughes is a machine designer in Rockford, Illinois, USA, and owner of Engineered Design Solutions, a provider of machine design contracting services. He has developed numerous AutoLISP and other software solutions to automate his workflow and increase his productivity throughout his years in business. Patrick developed the CadTempo time tracking program to aid his quest for further refinement of his processes, and invites you to investigate how it may help your organization. Find out more by visiting the CadTempo website at Reprinted with permission from Autodesk User Group International (AUGI), AUGI Hotnews, January 2012