SCM · Formalism · Coherence
A system can seem to function normally for a long period before tipping abruptly. Visible performance stays stable. Surface indicators do not flash. And yet something accumulates — an invisible debt that progressively erodes the capacity for recovery, up to the point where the slightest perturbation becomes irreversible.
The Systemic Coherence Model (SCM) proposes a formalism for making this dynamic observable before the rupture.
The mathematical core
Three fundamental variables: the active capacity A(t), which is the sum of liquid resources L(t) and debt D(t); the effective load C(t), the product of tension Θ(t), rigidity R(t) and blockages B(t); and the systemic margin M(t), defined as:
M(t) = 1 − C(t) / A(t)
When M(t) → 0, the system approaches saturation. When M(t) < 0, the load exceeds the available capacity: pre-rupture has begun.
The variable D(t) captures what surface indicators do not show: deferred commitments, repairs not carried out, incomplete recovery loops. A system can have a high L(t) and a high D(t) — it looks wealthy while its real active capacity is eaten away by its accumulated debt.
The systemic zones
Reading the index distinguishes four zones: the comfort zone (M > 0.5, the system absorbs perturbations without feeling them), the adaptation zone (0.2 < M < 0.5, the compensation mechanisms are active), the pre-rupture zone (0 < M < 0.2, the margins are nearly exhausted) and the rupture zone (M ≤ 0, the load exceeds the capacity).
The modular extensions
The SCM is designed as an extensible framework. Several modules can be grafted onto it: hysteresis (returning to the comfort zone costs more than it appears), cascades (the rupture of a subsystem increases the load on the others), propagation between coupled systems.
The SCM is an exploratory formal model. Its empirical calibration remains partial. Independent proxies for L(t), D(t), Θ(t), R(t) and B(t) must be selected with care to avoid circularity. The statements that can be confronted with data are explicitly documented in the GitHub repository.
SYNTHESIS
The Systemic Margin Index M(t) = 1 − C(t)/A(t) makes the pre-rupture zone observable before surface indicators reveal it. Its main interest is not predictive but diagnostic: it makes it possible to name and situate the dynamic of accumulating invisible debt that precedes systemic shifts.