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An new approach for design documentation

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degenn

Structural
Jul 26, 2009
39
Hi

I’d like to get some feedback from experienced engineers on a new tool we have developed for documenting calculations. It is a add-in for Word that allows updatable, unit based equations to be added directly in a Word document. It provides an alternative to spreadsheets, “black box” applications and specialized mathematical environments.

Equations can be simply typed into the document. Typing “M = 10kN * 5m =” is updated automatically to “M := 10kN * 5m = 50kNm”. The variable “M” can then be used in subsequent equations.

Updating any parameter in an equation will allow all equations to be immediately updated so that the entire document remains consistent. All equations are unit based so, for example, if you divide a force by an area, the result will automatically be displayed as a pressure.
The add-in is called Slydrule and we have been using it within our design office for some time. I’m keen to get feedback as to whether others see it as a useful compliment to other existing means of developing engineering designs.

By allowing calculations within a Word document, it allows the logic of the calculation to be explained in detail. The equation formatting allows the equations to be formatted exactly as they appear in a design code.

The areas where I have found Slydrule most useful is where there is some disagreement between engineers, perhaps the original designer and a reviewer. Allowing the design of a critical element to be documented clearly, with all assumptions, drawings and equations in a single, easily communicated document, I have found to be very helpful. This is particularly the case if the problem is becoming “legal”. Concise documents, with equations appearing exactly as they do in a design code, greatly helps the development of a legal argument.

Perhaps the biggest disadvantage of this approach is that it requires every step of the calculation to be detailed and understood. Many engineers tend to prefer “black boxes” that hide most of the detail. Having said that, once a “template” calculation has been created, it can be readily reused by changing the initial parameters.

This approach also is not geared to fast parallel calculations of similar elements in the same way that a spreadsheet can. It is best suited to detailed calculation of complex single elements.

It is however useful to act in parallel with a spreadsheet. A fully explained calculation of a single element is an excellent way to provide validation of spreadsheet calculations, not otherwise possible by a reviewer.
Example calculations, more information and a free download is available at
I look forward to any feedback you have.

calculation_axmhnb.png
 
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Are you aware of MathCAD? If so, what advantage do you propose? Price?

I hate spreadsheets because of the 'black box' issue personally so this approach is always preferred.
 
If the price of mathcad is the issue, there is always Smath. Essentially the same software at a price point nobody can complain about.

i have worked with TEDDS before and found it an absolute nightmare compared to mathcad/smath (tedds is like this, calculations emdedded in word)
 
Yeah - TEDDS sucks from memory. I actually hadn't heard of SMath - I'll have to check it out sometime. Matrix manipulation capabilities are an essential component of anything I'd ever consider using so if you're developing Slydrule further and don't have that functionality, I'd think it's fairly important.
 
Thanks for your replies. Yes I've heard of MathCAD, SMath and TEDDS and Slydrule is a bit like each but also a bit different to each.

Firstly, as a Word add-in, it is very accessible to everyone and extremely easy to learn. You can simply add a few equations to any document, rather than working in a specialized environment. A disadvantage of this, however, is it doesn't have the mathematical power of MathCAD. It only does the sort of equations you would find in an engineering code with basic mathematical operations, square roots, powers and trigonometry. This is all that is required for routine engineering calculations.

Being in Word, the quality of the final result is excellent and you have access to all the other features Word offers, already on your desktop.

With all calculations being unit based, this offers a considerable advantage over unitless Excel, allowing unit translation and error checking.

With the add-in you can build and edit calculations. Anyone else with the add-in can do the same. Once complete, the formatted calculations become embedded PNG files in the document, so can't be tampered with if you don't have the add-in.

I am looking to price the add-in, very reasonably, at $20, on the basis of a large potential market for a relatively simple tool.
 
A couple of years ago TTW (Taylor Thomson Whitting) in Sydney had a very similar add-in for WORD that was in a beta-testing, if I recall. It was mentioned on Eng-Tips too, but I cannot find the old thread.

I tried it and liked it. I shall give Slydrule a trial. Thanks.
 
I use SMath... even for simple calcs that I want to retain, and print off the page(s) using DoroPDF writer, also a free add-on that works like a printer driver and save the *.pdf copy to file. If the calculation is one that I will use several times in future, then I write it up as a real program.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik
 
I often use SMath for conversion... this little clip shows how you can enter a value, and by changing the units it automatically converts just using the "=" key and change units. I use this often... the metre is the default and no unit change is required (used lots for conversion) works with forces and everything else...

Clipboard01_ffnrqy.jpg


Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik
 
We use Tedds for this in our office. Their out of the box calcs are pretty variable (and have been getting worse as they try to make them more advanced) but as a word add in it's super handy. Not as ugly as mathcad and handles variables really well.
 
I've not used Teds and I don't use MathCAD, but SMath is quite elegant...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik
 
and a couple of other items I use with SMath... stuff that is off the page, does not print.

Clipboard01_aujuax.jpg


and I can use Windows 'snap shot' to paste information directly on the page, or off the page. None of the stuff to the right will print... including the stuff from Roarks won't print unless it's on the page.

Clipboard02_xhpucr.jpg


Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik
 
1a. How is the equation "anchored" within the text? Images and text wrap can be frustrating for a lot of Word users.
1b. Is this compatible with PDF printers? Sometimes images and attachments can be shown differently with different PDF drivers.

2. Does the equation auto-update as in SMath, MathCAD, etc?

3. I would be hesitant to use only because I would prefer using a dedicated Math tool as a program. For detailed calculations, I would use the standard reporting format (within a software program) or in a trackable method on a spreadsheet/math tool. Word is best used to report and present results, IMHO, not the step-by-step method.

4. I can see incredible value marketing this to academic or continuing education areas where the concerns in #3 are actually flipped. Beyond LaTeX, there is really no good way to present mathematical equations in-line with text.

This is an interesting concept and I may give it a try in the future. It's kind of bewildering how many of these "equation meets text" tools are now being pushed. At what point can we as engineers actually delineate between good communication and good presentation or numbers. Lol. More firms should be hiring technical writers, I guess...
 
Dik I don't know how you get so many images and snapshots to appear in your program and not have it bogged down. My experience with SMath and MathCAD have not been successful in having many snapshots within the program. The sheet will also reach an event horizon type limit where it just will error-out and shut down. I mainly use MathCAD/SMath to numerically check formatted or tabular results within an Excel sheet.
 
I've never had a problem with 'bogging down' and my programs are generally about a dozen pages and some in excess of 20... Maybe my computers are fast... nearly all set up for my son's gaming... even my laptops are fast. I do a lot of 'cut and paste' for my programs... the first page is a template I use for all of them...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik
 
@skeletron

You may find MathCAD works better if you bury stuff in areas and close them up. For example pulling section properties in from spreadsheets can be tidied up that way saving space and it used to be a tad faster for some reason. How big are your sheets though? 32 Gb of RAM probably helps too; I feel that such things are probably pretty inefficient on the memory front. If things get dire, I'm pretty sure turning off automatic recalculation will get you moving again - just recalculate at points where you really need to instead of each time you change an equation or a size here or there.

Regarding your point re: good communication or numbers - I don't think there needs to be a divorce between these two. I expect both. I've seen too many instances of people failing to pick up errors in their own calculations (particularly re-used spreadsheets which are very slightly inappropriate for the new arrangement) because the formula is difficult to read. I want to be able to read my calculations with minimal chance of misunderstanding. And when I'm checking someone's work for a discrepancy, I'd really prefer that to be the case too although it's of lesser concern.
 
Thanks everyone for your comments... I'll try to answer some of the questions raised.

Equations are typed in as simple text. Equations are a paragraph that uses a particular style, so other text doesn't get accidently get entangled.

Equation are type as simple text. For example -

A_bolt=\pi*D^2=​

An underscore makes a subscript and the ^ as superscript. Word automatically converts \pi to π on the fly. This allows simple, fast typing and the use of cut and paste, with repetition. The document remains fast and small.

An Update button does the calculations, from top to bottom, still keeping in normal text. Any change can be re-Updated. This update is under a second for 100 equations.

The appearance of the equations in the document is as shown in the image in the original post. This is achieved by clicking "Format". The laying out of equations is adequate for code type equations. It doesn't use Latex, which is heavy and slow (but great for integrals, limits and other advanced formatting).

The layout of the calculation is "step by step", as you would do by hand. It is not a programming language with loops and if/else structures. It is up to the engineer to read the results and check no equation invalidated if parameters are changed.

Being directly in Word, you have access to all the other tools available. Printing to any printer is a breeze, you have spell and grammar checks on your associated text and lots more.

The attached plot show on the what is initially typed on the left and on the right, the result after updating. Note the mixed units, correct processing of units and on the 4th line, the result is directed to a particular output unit, feet. This is really useful just working in both metres and millimetres.

calc2_pijngu.png
 
I just realised it... I don't have a need for formulas in a Word document, and don't think I ever had.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik
 
Mathcad and the other mentioned software are made for calculations. No question they are very powerful, especially in the hands of someone that knows how to drive them. However, if you are combining smart calculations with the simplicity and formatting features of Word, then I think there is potential.

There is Tedds for Word, but I have not tried it.

@degenn, I think you are on to something with Sliderule!
 
Hmm.. sorry if I'm missing the mark, but was the SPi account created with the sole purpose of bolstering degenn's effort to promote this tool?

Kinda looks that way.

----
just call me Lo.
 
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