Assembly vs. System

Archive of Older Topics Archive - Specifications Discussions #2
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Anyone want to suggest or point me to definitions of these terms? Are they synonyms or is there a difference?

Intuitively, I think of systems as being bigger, composed of assemblies; for example, a curtain wall assembly would be part of the building enclosure system. But by the same token, then, an insulated glazing assembly would be part of a curtainwall system, and we have curtainwall being both system and assembly.

Material and product give me similar headaches. The material portland cement is a component of the product concrete which is a component of a precast concrete wall assembly which is a component of the building structural system. But concrete is usually referred to as a material, not a product.

Material, product, assembly, system: are these wispy terms that vary with context, or is there a firm definition for each?

2

Systems consume energy. I think we use the catch-all term ‘systems’ in an architectural context too frequently. A building enclosure is not a system. Fire suppression is a system; it consumes energy. Lighting is part of a system. Engineers usually design systems; and sometimes manage design of assemblies.

Assemblies are what we architects are usually designing, and we should use that term more often. Architects usually design assemblies; and sometimes manage design of systems.

Where we have a number of assemblies that comprise a whole, we need another term besides ‘system’. ‘System’ is a poor choice methinks. I like ‘building enclosure’ more than ‘building enclosure system’. I like typing ‘methinks’.

‘Material’ and ‘product’ are neither system-specific or assembly-specific; and these terms can be used interchangeably.

3

Doug,

The only references that I find in a variety of dictionaries that speak of consuming energy in either of these definitions is from the Visual Thesaurus where it is assembly that is given the characteristic of using or creating energy about 6 levels of definition down from the primary definition.

Assembly: n 1: a group of machine parts that fit together to form a self-contained unit 2: the act of constructing something (as a piece of machinery) [syn: fabrication]

System: n 1: a group of independent but interrelated elements comprising a unified whole

Both of them from a Websters, but other sources similar.

The 2 words in all the references have similar defiitions - but interestingly none of the various sources have it where the 2 words reference each other.

I actually try to avoid the use of both of these terms, more inclined to avoid assembly because anything put together by anyone can be an assembly by the various definitions - whereas a system by the various definitions is speaking more to a unified combination of elements that make up, by design, an completed whole. That is to say, as the definition above for system is exactly how I use it where I never use assembly.

William

4

We do a lot of work with engineers/engineering consultants/wannabe experts, and that’s the place I’m coming from. I cannot over-estimate how different we architects and engineers communicate. In my office we cannot take ‘design community’ for granted (I’m one of six architects in a 40 person A/E firm - civil/municipal/heavy industrial). Half of our architectural work is under subcontract to engineering firms. Yes we have ‘architect jokes’ and ‘engineer jokes’. The last one was “an architect and two monkeys walk into a bar”. (He and I “had speaks” over that one).

That being said, and maybe our office is an extreme case, but for us a ‘system’ requires energy, and an ‘assembly’ is passive. Engineers and architects are not prohibited from employing ‘materials’, nor ‘products’.

But if an engineer is employing an assembly, he or she is gonna talk with the architect. If the architect is employing a system, he or she is gonna talk with an engineer. There’s more of ‘them’ than ‘us’, dang it.

Interestingly enough, we have to explain our ‘systems’ needs more often than they have to explain their ‘assemblies’ needs. Often we architects have to diagram the system for the engineer to design it. We get funny looks mostly because calculators don’t have ‘design’ buttons.

I made up this ‘system’ and ‘assemblies’ notion, but the simplicity of it has ‘saved my bacon’. The reference materials just haven’t caught up with us yet.

5

Aha!!!

Now I know why you like to type ‘methinks’.

The dictionary according to Doug -grin!

If it works for you, it works for you. Use it. However, I would personally shy away from it so that I did not have to defend it in at some arbitration hearing. Though as concepts, that’s not likely to happen. Someone woud have to be picking some pretty small points to try to base a claim on how you use the words.

The language is a living language - it changes over time. Like the thread on ‘must’ vs ‘shall’ - or that the entire use of shall in the living language as spoken is just about nonexistent anymore. Relegated to legal terms.

I guess if you have to ‘live’ with engineers and they outnumber you, you have to do what you have to do. Having been there, done that for about 5 years when I started out I understand.

William

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It’s probably not a coincidence I’m engaged in the ‘must’, ‘shall’, ‘will’ discussion with one of our venerable client’s attorneys at this time. Our client’s project manager says to me ‘you’re in the owner’s world now’. She’s very dear but I have to respectfully disagree.

It’s like ‘liquidated damages’. No jurisdiction around here prevails but we go through contortions to define what the damages are and why they’re reasonable for a tiny bit of leverage in arbitration. And every job is arbitrated!

7

In quickly reviewing MasterFormat 2004 section titles, I found no less than 12 instances of the word Assemblies, and 3 instances of the word System, in Division 09 alone.

None of them consume any energy, except what little I expended doing the search

8

Nifty Owner saying - only retort I know is in reference to Oz, “This aint Kansas, Toto.”

I have mumbled that on more than one occasion.

Oh my god - 2 Dougs on 1 thread, we are in trouble now.

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George, in his original post, said, “I think of systems as being bigger, composed of assemblies…The material portland cement is a component of the product concrete which is a component of a precast concrete wall assembly which is a component of the building structural system…”

A system isn’t necessarily bigger than an assembly or vice versa, nor is one necessarily a part of the other. While thinking in such terms might be useful in a particular context (as in an office, if everyone agrees on such specialized definitions and hierarchical relationships), since each term can mean many things, relationships may vary or be non-existent.

It may be more useful to think in these terms:

A product is something produced, implying a producer (and not just a manufacturer; could be a quarry, or a farmer, or an insurance company.) A product can be a material, and vice versa, but neither is necessarily also the other. For example, dirt is a material used in rammed-earth construction, but I wouldn’t think of it as a “product,” since it’s usually just dug up on site; an insurance policy may be a “product,” but it isn’t a “material” (other than the paper it’s printed on).

A material is something material, as opposed to immaterial. A design may be a product - produced by someone - but it isn’t a “material.”

Portland cement and concrete are products, typically, of a cement manufacturer and a ready-mix company. Both are also materials. And a better hair-splitter than I could even claim that both are assemblies (composed of various components) and systems (those components work together in some way that they don’t when separate). But that is not a particularly helpful use of either “assembly” or “system,” except in illustrating such a point.

An assembly is made up of things (components) that are assembled together. It may or may not be part of a system. It may or may not BE a system (e.g., the “solar system” is an assembly of a star, its planets and their moons, etc.)

A system is a combination of things (again, components) that work or interact together in some way, often for a common purpose. It may or may not consume (or produce) energy. A simple system would be the alphabet - a system of letters, which are used together to spell words. Most words are assemblies of letters. So, one can use a system to create assemblies. A system may or may not be, or be a part of, an assembly.

My point is, these words DO have basic or inherent meanings underlying most if not all of their “definitions,” which just “define” particular variations of those meanings. But those definitions or even meanings aren’t necessarily related to each other in fixed or simple ways. Maybe our concern should be with meanings, not “definitions.”

10

I gotta question Doug’s assertion that “‘Material’ and ‘product’ are neither system-specific or assembly-specific; and these terms can be used interchangeably.” OmniClass has distinct definitions and tables for each. http://www.occsnet.org

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Is that URL correct?

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As OmniClass defines them:

“Materials are basic substances used in construction or to manufacturer products and other items used in construction. Examples: Limestone, sand, aluminum, ponderosa pine, propane, polyethylene, fly ash.”

“Products are components or assemblies of components for permanent incorporation into construction entities. Examples: Aggregate, cement, concrete, asphalt, brick, door, window, electric cable, pipe, boiler, curtain wall system, paint, prefabricated brick veneer panel, vinyl covered gypsum board, demountable partition, and pre-engineered manufactured building.”

They do point out that some materials are also products, sand for example.

I am still pondering Doug’s breakdown. I am more comfortable with architect = assembly and engineer = system than I am with the energy consumption criterion, at this point. A motorized overhead door consumes energy, but is an architect designed assembly, for example.

13

George,
In ‘my’ system a motorized overhead door is a product. It is probably part of an ‘assembly’ that includes a wall, structural steel, etc. But it doesn’t constitute a part of a system.

Products can consume energy but materials cannot.

14

Doug-

Yeah, your assemblies are broader than what I had originally vaguely proposed. On the other hand, and to introduce yet another term, maybe your overhead door is a piece of “equipment” as much as it is a product, huh? Equipment hooked up to the electrical system, and part of the bigger wall, etc. assembly.

15

In what is becoming ‘my’ concept, a ‘product’ is attached to the building and is more or less a permanent part of it. An overhead door is a ‘product’ and not ‘equipment’.

The overhead doors are not part of a ‘system’ until door controllers are brought together, and a common control device is implemented. (That’s where the engineers may come in handy. Also, we architects probably owe the engineers a statement about how the owner wants the controllers to function.)

An item of ‘equipment’ is not necessarily attached to a building. An item of equipment may be procured rather than contracted. The UCC may be more applicable for equipment than a statutory warranty. For example, we’d like the owner to contract for it’s own hydraulic packers (even though these are mounted securely to the building), while we’d rather have the contractor responsible for the diesel generator that is ‘less’ attached.

16

So, are these distinctions important, or useful? Even if it were true (and it may well be), what is gained by using the concept that products can consume energy, but materials cannot?

Or, by arbitrarily limiting otherwise common but general terms to the idiosyncratic strictures of an unusually narrow “concept,” would we risk miscommunication? Wasn’t there a character in “Alice in Wonderland” who insisted that his words meant exactly what he wanted them to mean - nothing more, and nothing less?

Should we then include specific definitions of meanings and relationships (perhaps also stating what they can or cannot be, do, require or include) in the Project Manual, as one might define “provide” to mean “furnish, plus install”?

And, if we get so specific about the diffence between “products” and “materials,” will someone question whether it is proper to specify mere “materials” in “Part 2 - Products”?

Omniclass no doubt has valid reasons for being so specific. But its very specific definitions don’t govern the use of the English language outside its domain, even in the rest of the specifying world. Each context has its own set of meanings, with a degree of specificity or generality appropriate to the purpose. And the appropriate level is determined by common consensus - what people normally think when using those words in that particular context. Special definitions, except when well understood and clearly established, can thwart communication, not aid it.

17

‘Methinks’ the term “building envelope” is more descriptive without the controversity.

Ron

18

Isn’t their a book called “Refabricating Architecture” that dicusses this type of difference?

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I should have shared the reason for my initial post, I guess. Im putting together a community college level course on Construction Materials, with the goal of teaching relatively novice architectural technology students how to research, evaluate, select and specify products. It seemed useful to get a handle on some of the terms that Ill need to be using in that class. As this thread shows so far, although we use those terms every day, each of us has a slightly different slant on the meaning. I know what I mean, but Im not sure YOU understand what I mean.

After reading some of the responses, I am thinking Products needs a broader meaning. Everything used to construct a building is a construction product, as defined or implied by Part 2 Products. Materials are more elemental, or fundamental: Products are made of materials, as is already defined or implied in Section Format, with some overlap in some sections, like sand, or concrete. That seems fairly clear and easy to understand, and using Section Format is a good classroom tool.

The assembly vs. system original question is still fairly murky. When I write an MBR roofing section, including all the various membranes, mastics, flashings, insulations and so forth within the one section, is this a roofing assembly or a roofing system? Doug would say assembly, Robert would say it is both, and William would prefer to avoid both (to put words in your mouths).

Thanks for you comments so far. Any additional thoughts would be welcome. I have until the Spring semester before I have to stand up in class and speak definitively on these definitions.

20

There’s something to be said for avoiding needless distinctions.

“Assembly” and “system” are useful words, but is it really useful to narrow them down into “technical terms,” with definitions so specific that they no longer mean what most people would think? There is so much overlap in these terms that trying to separate them into distinct categories does more harm than good.

Part 2 is called “Products.” I can think of no reason it could not have been “Materials,” which if anything is probably more inclusive (but not necessarily more useful).

What I tried to show above (apparently without much success) is that unless there is something significant to be gained - some purpose to be achieved, problem to be solved, or misunderstanding to be clarified - making these unnecessary distinctions by arbitrarily re-defining common terms is just going to lead to greater potential for misunderstanding.

It’s not only useless, like speculating on how many angels can stand on the head of a pin. It’s counterproductive.