Thursday, 20 December 2012

Specifying a Sandwich

Would this sandwich meet the brief?
With NBS Create you can specify building fabric, the landscape, minor civils, mechanical and electrical engineering - but the big question is... can you specify a sandwich?

Well surprisingly NBS does not have template specification clauses or detailed technical guidance for sandwich specification. But considering something as simple as a sandwich illustrates some interesting specification principles. Also, if something as simple as a sandwich is quite involved and makes you think - then imagine specifying a curtain wall or air conditioning system?

So - consider a sandwich... (and if you could avoid the pun - please take this with a pinch of salt*)

Figure 1 below shows that the brief for the sandwich has been brought through digitally to help the specifier. An excellent specification template set of clause items exists that allows the specifier to select different structures of sandwich. Is this an open top, a standard two slice or even a double decker sandwich? The "Middle layer" is being removed in the example below as the brief clearly states that this is a standard sandwich.
Fig 1 - Viewing the brief and determining the basic structure of the sandwich
Figure 2 below shows that the specification system has suggested "products" to construct the sandwich from. The specifier is selecting wholemeal bread over the less healthy white or more boring brown bread alternative. The property sets within the "system outline" clause have a hierarchy - it can be seen that the wholemeal bread is part of the base layer.
Fig. 2 Selecting the products
Within each product option the user may not simply want one product. Sandwiches would be pretty bland if you could only have one filling. In Figure 3 below the specifier is selecting not one, not two - but in fact three fillings. Cheese, ham and tomato.

As each selection is made, then the corresponding product clause is brought into the specification. This check box/additive way of working means that clauses that are not required (say a clause specifying a slice of beef) are not accidentally left in the specification by mistake.
Fig 3 - Add multiple fillings
By this stage we now have an outline specification for the sandwich (as shown in Figure 4). Not enough to go to tender with if real quality is going to be achieved. But enough information to give a good indication of what the intent is an early stage. Each of the individual "products" have their own clauses that allow further detail to be added.
Fig 4 - The system outline is complete
Two methods of specifying products are shown in Figure 5. For the butter, the specifier is not fussed on the brand of butter - just some of the important properties. However, for the bread the specifier would like a specific manufacturer (Hovis) and also specifies some variations within that brand.
Fig 5 - generic vs proprietary specification of products
And of course, putting a sandwich together is a skill. Too much butter and you ruin it. Not enough and it's going to be pretty dry. So the specification goes down one more level so that the execution can be clearly stated (shown in figure 6). Notice that the relationship between the butter product clause and the butter execution clause exists.
Fig 6 - Specify the workmanship
I think the analogy can stop there. But you could go further and specify the overall performance of the of the sandwich (tastiness, overall crunchiness, expected life…) or how to complete the sandwich (put the sticker on) or whether samples and spares were required etc…

This sandwich definitely doesn't
meet the brief.
Also, how is each item classified so the café owner knows how many slices of ham they have sold each year and how this compares with the ham sold in their sister-café. A big well-structured spreadsheet/database could hold this data and the café owner could filter by the classification pick-list.

Maybe the big spreadsheet/database could be called SOBie - Sandwich Operation and Building Information Exchange format?

[* Apologies for the terrible attempts at humour - but it is nearly Xmas]

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