Choosing a product — menus and defaults
How Custom options, mappings, hard limits and conditional defaults decide a menu.
6 rules, in register order, from R32 to R63; numbers do not run in sequence. Back to the index.
R32 — A “Custom” option is never ruled out, in any menu
It is what keeps any enquiry quotable when nothing else in a menu survives. Custom is chosen for a stated value when a person picks it, or when the line’s product offers none of the materials the customer named (R76).
R33 — A menu where every option is ruled out is a line-level problem
“This family is wrong for this duty”, not an empty dropdown.
R60 — A “Decided by” mapping limits a header to the answers named for the deciding choices
A mapping may name more than one deciding header, and then applies only while every one of them is at a choice it names. Where several mappings that apply name different answers, exactly one is the default. A choice, or combination of choices, no mapping names leaves the header open.
Mappings that together involve more than 10,000 combinations of choices cannot be checked for a single default, and publishing is refused until some conditions are removed.
R61 — Where the default does not suit a process-factor value, a conditional default covers it
If a header’s default does not suit a value of an options factor (Solid, when the default suits only Liquid and Gas) and more than one option does, the header needs a conditional default for that value before the datasheet can be published. An option naming no values for the factor suits every value.
R62 — A hard limit rejects an option, even when the customer asks for it
An option’s hard limit is the range it can work in — PFA lining at −1 to 2 bar. When the enquiry’s answer falls outside it, even partly (−0.5 to 5 bar), the option is not used and the line reports the conflict.
On a requirement line the customer’s request stays, marked not offered by that product (R78); a limit broken only on an assumed value, or on a library value of a fluid no person has confirmed, warns.
R63 — Conditional defaults choose among the allowed options; the first matching rule wins
A header’s conditional defaults are tried in order. A rule applies when the enquiry’s answer meets it — for a range, when the two overlap — and its option is still allowed. It outranks a “Decided by” mapping’s default and the header’s own default, but never overrides what the customer asked for.