SSM-Audit – Case Study A: Stability Debt in a Collapsing Firm (4.1A)

Scope (anonymized). A multi-year storyline where headline revenue stayed large while foundations weakened. We keep classical values identical (phi((m,a)) = m) and surface early warnings via a bounded lane a and a composite index. No third-party data is embedded here; full, stampable artifacts are available via the repository link below.

What we show (executive view).

  • Band slide from A+ → A- → A-- well before the final break.
  • Strength lens S(m,a) := m*a flips sign while revenue m is still high.
  • Deterministic math and order-invariant rollups so the same lane appears whether you run batch or stream.

Invariants (non-negotiable).

collapse:  phi((m,a)) = m                  # value is sacred
clamp:     a := clamp(a, -1+eps_a, +1-eps_a)  with eps_a = 1e-6
fuse:      a_out := tanh( (SUM w*atanh(a)) / max(SUM w, eps_w) )  with eps_w = 1e-12
bands:     A++: a>=0.75; A+: a>=0.50; A0: a>=0.25; A-: a>=0.10; else A--
hysteresis: promote if delta_a >= +0.05; demote if delta_a <= -0.05

KPIs and lanes (declared once, choose 2–3).

# Revenue (level) — residual vs early baseline
residual:  res := Revenue - (beta0 + beta1*Time)
scale:     s := 1.4826 * MAD(res)
lane:      a_rev := tanh( k_rev * ( 1 - |res|/s ) )

# Liquidity
lane:      a_liq := tanh( k_liq * ( Current_Ratio - 1.0 ) )

# Leverage
lane:      a_lev := tanh( 1 - |Debt_Equity_Ratio| / b_de )

# Optional diagnostic — Cash coverage (for narrative only)
q_cov := CFO / max(eps_cash, |min(0, CFI)|)
a_cash := tanh( k_cash * q_cov )

Choose modest defaults (documented once): k_rev≈1.2, k_liq≈2.0, b_de≈2.0, k_cash≈0.5, eps_cash≈1.0.

Composite stability index (one-look).

a_index := tanh( ( atanh(a_rev) + atanh(a_liq) + atanh(a_lev) ) / 3 )

Strength lens (for ranking and sign flips).

S(m,a) := m * a

What the timeline shows (anonymized narrative).

  • Early (calm): Revenue residuals are tight; a_rev high; leverage/liq lanes positive → a_index in A+.
  • First downgrade: Residuals widen and leverage tolerance compresses → a_index slips to A- while revenue remains large.
  • Sustained distress: a_rev → ~-1 and leverage lane turns negative; a_index sits in A--.
    Strength S(m,a) turns negative despite sizable m, signaling misaligned growth.
  • Late: Liquidity finally softens; the composite remains in A-- until after restructuring.

Actions this would have triggered (examples).

  • At first band drop (A+→A-): tighten credit terms, curb concession creep, gate capex; weekly reconciliation cadence.
  • At sustained A--: formal turnaround track; independent policy audit; asset/liability program with stamped, replayable logs.

Calculator-fast replication (no data embedded).

# Step 0 — Fix knobs once
eps_a=1e-6; eps_w=1e-12; k_rev=1.2; k_liq=2.0; b_de=2.0

# Step 1 — Fit early baseline for revenue
fit Revenue ≈ beta0 + beta1*Time on an early calm window

# Step 2 — Lanes (clamp before any atanh)
res := Revenue - (beta0 + beta1*Time)
s   := 1.4826 * MAD(res)
a_rev := clamp( tanh( k_rev * ( 1 - |res|/s ) ) )

a_liq := clamp( tanh( k_liq * ( Current_Ratio - 1.0 ) ) )
a_lev := clamp( tanh( 1 - |Debt_Equity_Ratio| / b_de ) )

# Step 3 — Composite and strength
a_index := tanh( (atanh(a_rev) + atanh(a_liq) + atanh(a_lev)) / 3 )
S_rev   := Revenue * a_rev

# Step 4 — Bands + hysteresis gates
band := band_from(a_index) with promote>=+0.05, demote<=-0.05

# Step 5 — Order-invariance (rollups)
# If aggregating months/quarters: use the U/W fuse on lanes (weights per policy).

Artifacts you can obtain from the repository link (no dataset here).

  • Minimal scripts to compute a_rev, a_liq, a_lev, a_index, S(m,a).
  • A manifest with knobs and knobs_hash.
  • Optional stamped CSVs (time,kpi,m,a,band,knobs_hash,build_id,stamp) for replay.

Navigation
Previous: SSM-Audit – Case Studies: Strategy & Generic Guidance (4.0)
Next: SSM-Audit – Case Study B: Growth Steady, Foundations Eroding (4.1B)


Directory of Pages
SSM-Audit – Table of Contents


Frequently asked questions
SSM-Audit Q & A


Explore Further
https://github.com/OMPSHUNYAYA/Symbolic-Mathematical-Audit

Disclaimer
Research/observation only. Not for operational, safety-critical, or legal decision-making.