A Generic-Constraint applies to a defined Scope.

Alternative Names

Concept Number: *245
English Master: Generic-Constaint
Synonyms, Variations & Acronyms: System-Level-Requirement Constraint Derivative Source


It is tailored in interpretation or specification at the detailed Level.



Figure: three simultaneously applicable Generic-Constraints, leave one area of common “OK” territory for more specific decisions to be made, such as specific Requirements and designs.


Requirements Class, Parameter, {Requirement.Constraint.Generic}


For example:
(1) a corporate Policy Constraint which applies to all corporate projects:
Corporate Quality 2. All Product-Value Levels shall be clearly better than our competitors.
Note that the precise Product-Value Levels needed will depend on the competitor Levels, which will be unknown initially and will vary in time. So this Constraint requires tailoring; and is dynamically Changing through System lifetime.

(2) a contractual Requirement which applies to the entire contracted project.
Contract 2.3.4: all System components must be legal import in all European Markets.

(3) a legal Constraint which applies to products made in your country.
Euro Law 2001-3.4-334: No components, including imported components can use illegal Child Labour, even if assembled in another country by a supplier or customer.

Sub-categories [Global-Constraint]:
The potential Global-Constraint sub-categories are entirely open to the needs of the project. But there are some categories, which are typical and frequent.


1. Performance/Product-Value and Cost Constraints.
The distinction here is that the Global-Constraint specifications have wider Scope than any of the non-Global-Constraint specifications.

2. Other Global-Constraint categories: Legal, National, Market area, Competitive, Partnerships, Product Line Architecture, Design, Interfaces, Cultural, Ethical, System Component Constraints, Financial, Large Customer Constraints, System-wide, Corporate Policy, Standards, and many more possibilities, as you find useful. Again the distinction is wide Scope.

Corporate Reliability:
Type: Global Product-Value-Constraint.

Scale: Mean Time Between Failure (MTBF).
Tolerable [All Corporate Branded Products] 30,000 hours <-
Corporate Quality Policy.

This would make invalid any attempt to specify, as a local Product-Value-Requirement:

Product Reliability:
Type: Product-Value-Requirement.
Scale: MTBF.
Goal [Product XX] 20,000 hours <- Customer Contract.
Wish [Product Next Generation] 40,000 hours <- Marketing Long Term Plan.

The above Requirement would have to be adjusted to the minimum of 30,000 hours MTBF in order to satisfy the corporate minimum Product-Value (the Global Product-Value-Constraint) for Product XX and not hurt their brand image. But, the local Requirement for “Product Next Generation” would not need to be adjusted to comply with the current corporate Global Requirement, as it is an improvement over the corporate criteria.

We could explain this adjustment to people who might not otherwise understand why we had increased the specification beyond the customer”s Wish.

Product Reliability:
Type: Product-Value-Requirement.
Scale: MTBF.
Goal [Product XX] 30,000 hours <- Customer Contract
& Corporate Reliability.
Constraint: Corporate Reliability.
Stakeholder: Corporate Quality Director.

Some other examples:

GF1: Type: Global Function-Constraint:

Defined: The Product must be a mobile telephone and not wander into replacing or supplementing computers or entertainment or automated guidance Systems.
Rationale: this would Impact other of our business areas and partnership agreements with Company X and Company Y. <- Corporate Product Policy Feb 20 20xx. Paragraph 33.4

GF2: Type: Global Function-Constraint:
Defined: The Mission is strictly limited to scientific exploration of our own planet and must not deal with other planets or solar Systems.
Rationale: this is NASA and JPL territory.

GSC1: Type: Global System Constraint:
Definition: No aspect of the System can threaten sister company products, or national laws in any way: this includes Product-Value, costs, targeted markets, technology selection and manufacturing and disposal Processes; but is not limited to the foregoing list of potential specific concerns.
Rationale: Company Product Development Policy <-- CDP Feb 20 20xx, 3.44.


Illustration text: Architects make System-wide decisions, which must be respected by all other engineers. For example, “System interfaces” to enable safe, fast {change, tailoring, extension, development steps}. Design engineers try to reach Product-Value targets, within the specified Cost Requirements, for specific subSystems.

Type: Global Product-Value-Constraint.
All <product> Product-Values must be <obviously better> than all our <competitors>.
This is a Constraint on how low any specific Product-Value Level can be planned. Notice this Level varies with the competitorsProduct-Values.

This statement might also be directly specified as a Constraint specification for all Product-Value-Requirements. But, more likely a set of different Constraint Requirements will be set within the framework provided by the Global-Constraint “GC”.

Notes(a conscious reuse of “set” parenthesis)

The set parenthesis (“{…}”) can be used singly, or together, when placed on an Attribute arrow icon Scale (--{----->).

Note 1. Icons: there is no conflict with use of { } for other reasons ( set , spawns, combines) because the Generic-Constraint icon is only used on an Attribute Scale (---->).

Note 2. Icons: compare the use of ----[[----]---- as Keyed-Icons for Limit, which is a Fundamental Constraint.

Note 3 Icons: The simultaneous existence, as a Requirement-Specification, of both Fundamental-Constraints and Generic-Constraints is quite possible. One Constraint specification can even be both (Fundamental and Generic). They might even apply simultaneously (Time Qualifier)and with same qualifiers otherwise (Place, Event)


In specific instances, the icons of specific synonyms such as Tolerable (->>) and Goal (->) can be applied to express Generic-Constraints..

The open side” (this side}” or “ {this side)”, is the direction of acceptable Attribute Levels. ----NO {-----OK-----}NO-------
Rationale [Generic-Constraint]: this classification is used to emphasize the fact that the actual practical Constraint applied at the local Level of specification will need to be tailored to that specific Level. It will have to be “generated” depending on the Generic-Constraint specification, and the corresponding local Context. This is the “Derived-Constraint” (a specific local Constraint derived from a Generic-Constraint).

Note 1. Consequence Analysis. Generic-Constraints are generally (not always) set by powerful Stakeholders and are generally not subject to much negotiation. Of course they can be in conflict with each other, and with any other Requirements specifications or System environment realities. So they need to be examined in terms of their design consequences, costs and Product-Values. If necessary, some feedback, to the Stakeholders concerned, will be necessary, and may Result in modification, ignoring or removal of the Constraint.

Note 2. Outer Border. A Generic-Constraint is a specification, which “draws a border” regarding Requirements or design, but which allows more-specific Requirements (which can be specific Constraints on Requirements or design) to be specified inside that border.

Note 3. Probably Global. Generic-Constraints usually consider interests, which are broader or more fundamental than a specific project or Product (or other “Lower-Level” or “shorter-term” perspectives). For example interests of a Product line, or national laws and customs. To the degree they have wide application, they are also classified as Global.

Note 4. Conflict Analysis. In cases of a conflict between any Generic-Constraint and any other specification, a Generic-Constraint probably has a Priority which is higher than any conflicting specific Requirement or design. But this entirely Depends-On the exact nature of the information about the Requirements which determine Priority {Authority, Source, Priority, qualifiers [such as when, where and event Conditions] }. To the degree which it does have Priority over others, it is also classed as a Fundamental Constraint.


---X {----}Y---






This Concept entered by Diane O'Brien.

Created by system. Last Modification: Thursday 11 of July, 2019 18:31:22 CEST by Admin (Kai).

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