Webel: SysML: Heard of "follow the money"? In MBSE we "follow the flows"! Identify requests, data packets, message, signals early on and use ItemFlow as often as you can wherever you can! Adopt a signal processing mindset throughout (systems thinking).
Webel: SysML1.7: Port contract matching is Feature-based, not Type-based. There's nothing particularly magical or special about use of an ~InterfaceBlock on a "conjugating" SysML Port, it's just a convenient way of managing one-to-one Feature matching!
Webel: Psy/MPsy: Psychrometrics for Mathematica: Convention: Option variable names are prefixed with '$opt$psy'
Webel Best Practice: Mathematica: Options are encapsulated as a String variable with the prefix '$opt', and have a related '$info$opt$' String (help), '$lab$opt' String (label), a 'def$opt' default value expression, and an optional '$warn$opt' String.
Mathematica: TIP: Protecting against computations breaking verbosely because of Null, None, Undefined. And about using Undefined as a return policy.
Webel: Mathematica: TIP: Maintain a Package library of Quantity variables for frequently used units using a naming convention unit$[unitSymbol] and unit[DescriptiveName] or unit[Acronym]
Mathematica: Webel: You CAN/MAY use $ in variable names and function names - just not as the first character before a Capital - and it's extremely useful. You won't get sent to Azkaban prison if do you use a $ character!
In the Webel terminology for a basic control loop there is an 'aim' value (controlled via an actuator) and a 'got' value (a value read from a sensor). The 'got' value is NOT necessarily exactly the same as the actual physical value.
SysML: When using Property::defaultValue and Property::redefinedValue to carry a "shadow hierarchy" of redefinitions across an entire system hierarchy, considering using a user-defined keyword such as «configuration» or «scenario» on each redefining Block
Webel: UML/SysML: Navigation: ALWAYS offer a way out of a diagram (usually up a hierarchy, but possibly across) using a navigable symbol (linked to a diagram) and/or a diagram symbol. Avoid "cul-de-sacs"! [But beware of shared package cross-dependencies]
SysML: HOWTO Safely incorporate ConstraintBlock equations from a library into a project with local ValueType variants: CASE: SysPhS vs ISO-80000 ModelLibrary
Webel: SysML: Electronics: DO NOT represent a jack/socket as a dumb proxy. Imagine it can introduce some signal noise or other effect (such as buzz) to test it is a physical model.
In the Webel recipe for UML/SysML, the pattern of progressive redefinition of end Properties of Associations between progressively more specialised pairs of Blocks at the same level of abstraction is informally called a "redefinition ladder"