Relativized Systemic & applications


RSE versus Functional Analysis

Why Functional Analysis cannot master complexity

The limits

As soon as 1957 Gilbert Simondon was aware that functional analysis wasn't an appropriate framework to master innovation and complexity. He took as an example the implicit paradigm he discerned underneath the stream locomotive on one hand, and the internal combustion engine on the other.

While the first one may be thought in terms of a succession of operations, each one carried out by some dedicated mean, the last requires taking into account, when designing the cylinder head, several competing points of view: power supply, heat dissipation …

Functional analysis and stream locomotive

When the design of some artefacts results from competing points of view, it is no longer possible to think in terms of successions but it is necessary to be able to assess whether the resulting features do fit the requirements and constraints of each contributing points of view, separately considered.

Cylinder head and competing points of view

Functional Analysis relies on an « Aristotelian » way of thinking reality

RSE : introduction of relativities

RSE systematically introduces relativities in our way of conceptualizing, resulting from our finalities at work:

Dependancies mapping

Models no longer come as « true images of reality» but are unambiguously regarded as reflecting what we look forward to.

Physical entities no longer reflect the absolute organization of reality, as it is, but come as built concepts with operational efficiency:

RSE emphasizes the key role of experimentation as opposed to « common sense »:

Compative synthesis of RSE versus Functional Analysis

Methodological typing

Functional Analysis

Functional Analysis relies on “common sense”. Derivative applications pin around the concept of “function”, stemming from mathematics. Nevertheless, Functional Analysis does not endow “function” concept with any objectifiable precise meaning.

Functional Analysis does not define any consistent and comprehensive semantic to be shared between its different applications, such as:

All functional associated developments are based on the set Theory, which is inappropriate to physical modelling, as quantum physic puts it forth. As the consequence, Functional Analysis cannot be regarded as a valid starting ground to set up modelling methods conforming to scientific criteria.

Relativized System Engineering

RSE is a constructive, systematically relativized and formal method, which relies on RS (Relativized Systemic) mathematical algebra. Any RSE model, at any stage of development process, meets scientific criteria, so that it may be used as a reference to evaluate early prototyping for exemple, and from any viewpoint.

RS algebra is a non-commutative algebra stemming from a deep analysis conducted by Pr. Mugur-Schächter, of the cognitive situation entailed by quantum physic.

Two different ways of viewing Reality

Functional Analysis : a realistic credo

Material reality does exist and may be known, such as it is. Genetically, Functional Analysis comes as a Safety Analysis tool to qualify something already designed, not as a design tool.

A material entity may be broken down into other material entities, and so on. Reality organization may be fully described.

Relativized System Engineering : a relativized standing

Reality is a substratum we are inner part of, both physically and psychologically. It cannot be known on its own.

Any description results from a finality driven building process, out of traces attributed to the interactions between the entity to be described and the measure devices or our biopsychic perceptions. What is respectively ascribed as properties to the first one and to the last one is a matter of convention resulting from established knowledge and theories.

We devise verifiable organizations of Reality according to commodity and efficiency criteria. This characterizes so much innovation as knowledge building processes.

Physical reality and cognition

Two concepts of description

Functional Analysis

Any physical entity is described as a “component” to which “functions” allocated. This “component” may be broken down into other “components” and “functions” further refined independently from any context.

“Functional states” may be used to specify different ways of producing “outputs” from the same “inputs”.

Functional analysis and mixing views

Even when some “component” is dedicated to a specific “service function”, it is not possible to objectify the corresponding viewpoint on the “component” in terms of correlations of physical interactions. What is the impact of some “input” on the “outputs” in a given situation that is not explicitly defined?

Functional analysis architecture comment

Relativized System Engineering

Any physical entity “exists” relatively to a context, just as a causal node of the stable correlations in space and time which can be registered or publically testified, between different observables.

A life phase (a specialization of the concept of physical state) is regarded as a lasting way of “being” of such an entity, relative to a given viewpoint and a given future, such as it can be conceived. By construction such a life phase is physically reproducible.

A life phase wholly describes the associated physical entity from this viewpoint. It stands as the physical model of causal node that associates a view with the external parameters which condition its values in a deterministic or a statistical way. The organization of the different life phases makes it possible to describe the whole dynamic of the entity under study.

The RSE conceptualization levels make it possible to focus on the semantic level while connecting it explicitly to the physical interactions level (transfer level) to ensure objectification.

Abstraction levels

A model which specifies the different possible chaining of the life phases relative to a viewpoint, depending on context and events.

Life phases

System design

Functional Analysis

System design boils down to two different kinds of breakdown structure without any rule to ensure consistency:

“Functional” breakdown is supposed to formalize the original analysis framework used in Safety Analysis consisting in “external functional analysis” on one hand and “internal functional analysis” on the other. Nevertheless all the “functional” breakdown levels between top level “functions” supposed to describe the Product and allocated “functions” remain deprived of any meaning.

As a corollary top “material” breakdown structure, above the level at which “functions” are allocated to “components”, remain irrelevant.

System design eventually consists in allocating “functions” to “components” but without any rule managing further refinement of the design: no generally specified constraints ruling “allocated functions” breakdown and associated “component” breakdown.

Functional analysis framework

Relativized System Engineering

System design results from a viewpoint on the set of Statements of Work (SoW) which motivates the Product development. They are as many systems as spheres of operation defined by the Organization, each one in charge of a finite set of Product features.

SoW formalizes the stakes associated with Product usages either from Human viewpoint (bio psychological description: man is the measure instrument) or from technical viewpoint (technical and scientific description relying on standardized measuring devices). RSE manages explicitly the conventional dependencies between both kinds of physical description.

Each system design tackles the Product development in an autonomous way and it is up to the architecture design to define and optimize shared material resources. This organized one-on-one debate between needs driven design processes and resources optimization, results in compromises and arbitrations.

This convergence of autonomous viewpoints toward a single Product is made possible by the RSE concepts of relativized description, system specification and system design. They make possible to combine or to isolate at will standalone physical descriptions, at different conceptualization levels, at any stage of development process.

RSE framework


Functional Analysis

Functional Analysis considers it is possible to fully describe the expected behavior of the Product. To meet this goal, it allocates to the same “component” and consolidates “functions” resulting from different "functional" breakdown structures, each of this ones corresponding to a given viewpoint. As a result, the different stakes get mixed up and can neither be individually traced in the design nor tested or evaluated during IVVQ.

Any modification or new need resulting in new allocations entail a tedious reworking of the “component” functional structure with no straightforward measurable impact.

Functional analysis architecture comment

Relativized System Engineering

An entity description explicitly results from a finite set of viewpoints aiming not at exhaustiveness but at relevance against the goals.

Any entity may be wholly described at design time and evaluated during IVVQ from one or several viewpoints without any mixing. Any change as an impact limited to the relevant viewpoints.

The retro engineering of above mentioned example within RSE framework has led to free autonomous physical description of the same ECU usable for testing (IVVQ).


These concurrent relativized descriptions of the same physical entity were made possible by the combination of key RSE concepts:

Inner view on RSE modeling


Functional Analysis

Functional analysis doesn’t deal with the crucial problem of the relationship between models and facts which determines nevertheless the assessment of the Product eventually realized against the needs and constraints which have motivated its development.

Operationally such a connection is made possible only when:


As a corollary:

Functianal component model

Relativized System Engineering

Any RSE concept (entity, system, state) may be physically described.

A requirement is defined as a specific generative and qualification process which stresses a dynamic or static feature of the entity to be described.

Requirements are organized according to the life phases structures which ensure consistency and make clear impacts and dependencies. This together with formal definition of the requirement concept make possible automated documentation generation out of models.

RSE puts forth a threefold approach to testing:

Complexity of implementation

Functional Analysis

When dealing with “big systems”, functional analysis leads to black-hole-like-models, which spin out of the designers’ control, impossible to understand and without identifiable links with factuality: a conceptual chaos, a primitive stew of “functions” and “flows” never achieved.

Functianal Analysis black hole

Relativized System Engineering

Each viewpoint remains autonomous and different viewpoints may be combined at will to highlight interferences. Together with conceptualization levels, this feature makes it possible to master the modeling of so called “complex” situations.

Based on a brand new physical interpretation of probability and entropy, a complexity indicator may be computed relatively to a finite set of views on the same entity. This may be used so much to qualify an existing resource against a set of goals as to evaluate a design to keep development process under control.

The RSE complexity measure is relative to:

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