spc_run_chart.png

# ===========================================================================
# MODULE 09 · SPC Run Chart
# ===========================================================================
print("[09] SPC Run Chart ...")

months = np.arange(1, 25)
# Wait times: first 12 months around 45 min, next 12 months around 32 min
wait_times = [
    43.5, 47.2, 41.8, 46.0, 48.5, 42.1, 45.2, 49.0, 44.1, 46.5, 43.0, 45.5,  # Baseline (median 45.35)
    34.5, 31.2, 33.8, 30.5, 29.1, 32.4, 35.0, 31.8, 30.0, 32.5, 33.1, 28.5   # Shift (all below baseline median)
]

fig, ax = plt.subplots(figsize=(10, 4.5))

# Plot all points and lines in primary color
ax.plot(months, wait_times, "o-", color=PRIMARY, linewidth=1.5, markersize=5, label="Monatliche Wartezeit")

# Baseline median (first 12 months median)
baseline_median = np.median(wait_times[:12])
ax.axhline(baseline_median, color="#6B7178", linestyle="--", linewidth=1.2, label=f"Baseline-Median ({baseline_median:.1f} min)")

# Highlight the shift (months 13 to 24 are all below baseline median)
shift_months = months[12:]
shift_times = wait_times[12:]
ax.plot(shift_months, shift_times, "o", color=EVENT, markersize=7, label="Sonderereignis: Shift (N=12)")
ax.plot(shift_months, shift_times, "-", color=EVENT, linewidth=2.0)

# Labels & styling
ax.set_xlabel("Monat")
ax.set_ylabel("Mittlere Wartezeit (Minuten)")
ax.set_title("SPC Run Chart: Wartezeit Notaufnahme nach Triage-Einführung")
ax.set_xticks(months)
ax.set_xlim(0.5, 24.5)
ax.set_ylim(20, 60)
ax.grid(axis="y", linestyle=":", alpha=0.6)

# Annotations
ax.text(12.5, baseline_median + 1.5, "Einführung Triage-System", color=EVENT, fontsize=9.5, fontweight="semibold", ha="center")
ax.axvline(12.5, color=EVENT, linestyle=":", linewidth=1.2)

# Legend
ax.legend(loc="upper right", frameon=True, facecolor="white", edgecolor="none")

save(fig, ASSETS / "09-deskriptive-statistik" / "assets" / "spc_run_chart.png")