The use of a decision matrix to prioritize SOR items in the boat design process

[TANSL]

The first step is to make a list of the Statement of Requirements (SOR). The second is to make a decision matrix, where each item has a weight based on its importance for the overall design.

Interesting method of work, I would love to know more about its use in practice.

< Note: this thread was split from Hi all from Sweden https://www.boatdesign.net/threads/hi-all-from-sweden.59522/ >

 

[gonzo]

It is the standard method for engineering. You can google it and find millions of links.

 

[TANSL]

You were very right, Gonzo, I searched on Google and found the following :

"Decision-matrix method
From Wikipedia, the free encyclopedia

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The decision-matrix method, also Pugh method or Pugh Concept Selection, invented by Stuart Pugh[1], is a qualitative technique used to rank the multi-dimensional options of an option set. It is frequently used in engineering for making design decisions but can also be used to rank investment options, vendor options, product options or any other set of multidimensional entities.

A basic decision matrix consists of establishing a set of criteria options which are scored and summed to gain a total score which can then be ranked. Importantly, it is not weighted to allow a quick selection process.

A weighted decision matrix operates in the same way as the basic decision matrix but introduces the concept of weighting the criteria in order of importance. The resultant scores better reflect the importance to the decision maker of the criteria involved. The more important the criteria the higher the weighting it should be given. Each of the potential options are scored and also multiplied by the weighting given to each of the criteria in order to produce a result.

The advantage of the decision making matrix is that subjective opinions about one alternative versus another can be made more objective. Another advantage of this method is that sensitivity studies can be performed. An example of this might be to see how much your opinion would have to change in order for a lower ranked alternative to out rank a competing alternative.

Morphological analysis is another form of a decision matrix employing a multi-dimensional configuration space linked by way of logical relationships."
​

After reading it, I do not understand how I could make so many projects without having used this method. I have become obsolete, there is no doubt.
Perhaps the OP will find it more difficult to learn this method than to develop the design. My advice is that, for the moment, you forget such a useful method and go the traditional ways. A complete and detailed SOR would be enough for anyone, as obsolete as I am, to help you.

 

[AusShipwright]

I think a decision matrix would be used for comparing similar designs to determine the optimum hull form based on any analysis performed. Purely objective.

At this stage the design drivers would be interpreted from the SOR and I don't think a decision matrix would make things clearer.

What other references do you have apart from this forum and your 2 similar vessels? I'd suggest building your resources and begin reading if you haven't already. A good start would be Dave Gerr's Boat Mechanical Systems Handbook and The Elements of Boat Strength.

 

[gonzo]

You were very right, Gonzo, I searched on Google and found the following :

"Decision-matrix method
From Wikipedia, the free encyclopedia

Jump to: navigation, search
The decision-matrix method, also Pugh method or Pugh Concept Selection, invented by Stuart Pugh[1], is a qualitative technique used to rank the multi-dimensional options of an option set. It is frequently used in engineering for making design decisions but can also be used to rank investment options, vendor options, product options or any other set of multidimensional entities.

A basic decision matrix consists of establishing a set of criteria options which are scored and summed to gain a total score which can then be ranked. Importantly, it is not weighted to allow a quick selection process.

A weighted decision matrix operates in the same way as the basic decision matrix but introduces the concept of weighting the criteria in order of importance. The resultant scores better reflect the importance to the decision maker of the criteria involved. The more important the criteria the higher the weighting it should be given. Each of the potential options are scored and also multiplied by the weighting given to each of the criteria in order to produce a result.

The advantage of the decision making matrix is that subjective opinions about one alternative versus another can be made more objective. Another advantage of this method is that sensitivity studies can be performed. An example of this might be to see how much your opinion would have to change in order for a lower ranked alternative to out rank a competing alternative.

Morphological analysis is another form of a decision matrix employing a multi-dimensional configuration space linked by way of logical relationships."
​

After reading it, I do not understand how I could make so many projects without having used this method. I have become obsolete, there is no doubt.
Perhaps the OP will find it more difficult to learn this method than to develop the design. My advice is that, for the moment, you forget such a useful method and go the traditional ways. A complete and detailed SOR would be enough for anyone, as obsolete as I am, to help you.

Students learn how to make a variety of decision matrix styles in a single class. <removed>

 

[TANSL]

<removed>.

I've never said that, reread my comment, please. It just seems to me that it's not worth spending even a minute on that technique to design boats.
Some people do not know that technique but design boats and others, apparently, master that technique but are not able to design boats. Paradoxes of life.

Posted on 12/06/2017 : In the paragraph removed by the Moderator, I was attributed, with the intention of ridiculing myself, a phrase that I had never said. Resorting to lies is not honest but doing it, in addition, to achieve a despicable end, is creeping.
After deleting the paragraph, the first sentence of my answer seems pointless, hence the current explanation.

 

[Angélique]

It just seems to me that it's not worth spending even a minute on that technique to design boats.

Hi my dear buddy TANSL,

I'm sorry to hear you don't understand the decision matrix method after you copy pasted so much info about it.

It's not a specific boat design technique as you write, it's a technique to make informed choices from many options in many fields, [and organize them by importance. ( = an addition taken from Gonzo's below post)]

If you want to learn and/or discuss about this specific method, then best start a thread about it, instead of distracting and hijacking this one by continuing digging into a side topic on a thread of an other forum member who started this one, and in this case to introduce himself. Thank you, [U]my friend[/U].

And please don't exhibit your regular rude behavior of derailing and hijacking other people's threads by side tracking towards your own interests, like you usually do.

If the OP [U]Magnus W[/U] wants to discuss this side topic on his thread, then I'm sure he's able to ask his own questions here.

Thanks again, my friend . .

 

[gonzo]

It is the most important tool to define a design. The SOP will provide the items to enter into the matrix which organizes them by importance.

 

[Angélique]

Hi Gonzo, I'll guess in the above post ‘SOP’ is a slip for ‘SOR’ . . ?

 

[gonzo]

Yes

 

[Ad Hoc]

Some people do not know that technique but design boats and others, apparently, master that technique but are not able to design boats. Paradoxes of life.

Nope it is simple.

Those that design boats without such....is simply an assembly. They gather up ideas thoughts without any indication or knowledge whether "it" will work went finished/built. Doesn't mean it won't it just means that zero real analysis has gone into it save for - i reckon that....or.....i think that.... type of design. It is what anyone can do, no experience required.

But design, real design, uses the design spiral, another name for the above. It is done naturally as the design develops. And not complex or complicated at all...very easy really.

And please don't exhibit your regular rude behavior of derailing other people's threads into side tracking towards your own interests, like you usually do.

Agreed...

 

[TANSL]

We all know, or should, that the design spiral is not the same as the decision matrix. The first is the logical evolution, the way forward, in the design process and the second is a decision-making technique.
I insist on my previous advice to the OP : do not complicate your life, do not waste a minute, learning the technique of the decision matrix because it will help you very little, or nothing, in the design process.

 

[Mr Efficiency]

Perhaps a user of decision matrices in boat design, will be kind enough to post an example they have personally employed for the purpose. That would be preferable to a snipe-fest.

 

[TANSL]

Perhaps a user of decision matrices in boat design, will be kind enough to post an example they have personally employed for the purpose.

I agree. In this way we all could evaluate if it is worth learning this "useful" technique.

 

[Mr Efficiency]

As a betting man, I am not confident one will be forthcoming !