Basic for evaluating the technical view of models

Delivery

Part of the delivery are Boxes, descriptions, manuals, sparepart lists and additional parts
Boxes give a first impression and are used to invite the customer to buy. Therefore the boxes need special attention in their layout. Most important is the size of any box, which should be in an adequate ratio to the contents. Thus a minimal size to shield the contents against damages (through packing/send for example) is as important as a maximal size, where a bad flavour can develop (" much ado about nothing").
The minimum size depends on type and size of the contents and, of course, the amount of add ons. Starting from a certain size the volume can be regarded as oversized:

For a evaluation-scheme, one could use a point-system according to (german) schools, where there are 15 points to be given totally: up to the given oversize 15 Points, every further 10% (referred to the given oversize) one point less.
Some examples:

a)Märklin-no. 3080 (shunting diesel Typ DHG 500 yellow):
L x B x H = 11,6 x 3,5 x 5,0 cm = 203 cm³(w/o slider); also delivered: manual/description. Resulting size: + 40% =284 cm³. The original box has: 15,2 x 5,5 x 8,0 cm = 669 cm³ This is 136% oversized and thus 1 point

b)Märklin-no. 4064 (sleeper-coach of the DSG, iron-plate):
25,6 x 3,7 x 4,9 cm = 464 cm³, limits: +20% = 562 cm³. The box has 26 x 4,0 x 5,4 cm = 562 cm³, thus 1% oversize, and 14 Points.

c)Märklin-no. 4279 (postal expresstrain-coach white/yellow, plasticshell):
27,4 x 3,5 x 4,8 cm = 460 cm³, limits (with descriptions/accessoirs): + 40% = 644 cm³. The box has here: 30,2 x 5,0 x 7,4 cm = 1117,4 cm³, 73% oversize and 7 Points.

When there are several articles packed together, as in train packages, the size sums as follows:

e)Märklin-trainpackage 3471 (RAm-TEE der NS DE1001):
1 motorized head, 2 Intermediate coaches, 1 controlcoach. Largest dimensions: 24,0 x 3,5 x 5,0 cm = 420 cm³ resp. 1680 cm³ for the complete train. Oversize: +40% = 2352 cm³. This train-package comes with manual and accessoirs. The box itself has staggered contents: 64,3 x 17,4 x 5,5 cm = 6154 cm³. Unfortunately this is 262% oversize and therefore 0 Points.

For a moderated ratio length/width has to be looked.
Further accessoirs one can document, but it isn't useful to evaluate that.

Documentation

Any article delivered should be documented. Especially those with mechanical and/or electrical functions need manuals/descriptions for service, use and repairs. Thus available documents are good remarks, missing bad ones. For the three parted system (descriptions with evtl. information about the prototype, maunals and spare part lists the system of points is easy: 5 Pts each for included in delivery, 2 Pts each for available upon request and 0 Pts for not available. Not all motorless models have printed matters included, and are thus not good evaluated. Spare part lists are also not always included, but extremely important for repairs beyond the common parts of use.

Service/repair/didactical value

Any operational use means wear of the movable parts. Wearing parts are used up quickly (therefore their name). At least, they must be accessible and cleanable easily and simply. If any other part hinders or prevent this, a service/repair/exchange isn't possible. Further, one can learn from the provided construction normally. The criteria are similar to the ones already mentioned. Therefore the following assignment of points:

Suggestion for service:

Suggestion for repair/exchange:

Suggestion for didactic (gears/propulsion-set):

Compatibility

Operation

Operation stands for the all-day use. Most important are speeds, noises; other characteristics are less important if they do not affect the operation. Noises are annoying, if they don't fit to the prototype or model, or if they are too loud. Unfortunately this can't be quantified. The same counts for steady/smooth running and special functions switched independently (if present) as well. For the minimum non-jerking movement a compromise is necessary, since even the prototype does below about 5 km/h. In order to get objective we should assign 15 points for v_min<=5 km/h, each km/h more means one points less.
Maximum velocities are not that unique due to very different factors to be involved. Even the NEM are using 100-140% of the prototype (gauge H0) at normated voltage (which itself isn't correctly defined for AC-operation!). Thus the following suggestions (note: if an electronic circuit allows vmax to be set, the max possible value is to be regarded):