Cost of Quality Analysis

import matplotlib.pyplot as plt
import numpy as np
from matplotlib.patches import Patch

categories = ['Total\nRevenue', 'Prevention\nCosts', 'Appraisal\nCosts', 'Internal\nFailures', 
              'External\nFailures', 'Warranty\nClaims', 'Quality\nProfit Impact']
values = [0, -45, -32, -28, -65, -42, 0]

initial = 1000
running_total = initial
bottoms, heights, colors = [], [], []

palette = ['#22c55e', '#3b82f6', '#f59e0b', '#ef4444', '#dc2626']

for i, (cat, val) in enumerate(zip(categories, values)):
    if 'Total' in cat:
        bottoms.append(0)
        heights.append(initial)
        colors.append('#3b82f6')
    elif 'Quality' in cat:
        bottoms.append(0)
        heights.append(running_total)
        colors.append('#22c55e')
    else:
        bottoms.append(running_total + val)
        heights.append(abs(val))
        colors.append(palette[(i-1) % len(palette)])
        running_total += val

fig, ax = plt.subplots(figsize=(12, 8), facecolor='#ffffff')
ax.set_facecolor('#ffffff')

x = np.arange(len(categories))
bars = ax.bar(x, heights, bottom=bottoms, color=colors, width=0.6, edgecolor='#e5e7eb', linewidth=1)

for i, (bar, val, bot, height) in enumerate(zip(bars, values, bottoms, heights)):
    y_pos = bot + height / 2
    if 'Total' in categories[i] or 'Quality' in categories[i]:
        label = f"${height}M"
        ax.text(bar.get_x() + bar.get_width()/2, y_pos, label, ha='center', va='center', 
                fontsize=11, fontweight='bold', color='white')
    else:
        label = f"${abs(val)}M"
        ax.text(bar.get_x() + bar.get_width()/2, y_pos, label, ha='center', va='center', 
                fontsize=10, fontweight='bold', color='white')

for i in range(len(x) - 1):
    y = initial if i == 0 else bottoms[i]
    ax.plot([x[i] + 0.35, x[i+1] - 0.35], [y, y], color='#9ca3af', linestyle='--', linewidth=1.5, alpha=0.7)

ax.set_xlim(-0.6, len(categories) - 0.4)
ax.set_ylim(0, initial * 1.1)
ax.set_xticks(x)
ax.set_xticklabels(categories, fontsize=9, color='#374151')
ax.set_ylabel('Revenue Impact ($ Millions)', fontsize=12, color='#374151', fontweight='500')
ax.set_title('Cost of Quality Impact on Revenue', fontsize=16, color='#111827', fontweight='bold', pad=20)
ax.tick_params(axis='y', colors='#374151', labelsize=10)
ax.yaxis.grid(True, linestyle='--', alpha=0.4, color='#e5e7eb')
ax.set_axisbelow(True)
for spine in ax.spines.values():
    spine.set_color('#d1d5db')

coq = initial - running_total
coq_pct = (coq / initial) * 100
ax.annotate(f'Total Cost of Quality: ${coq}M ({coq_pct:.1f}% of revenue)', xy=(0.98, 0.95), xycoords='axes fraction',
            fontsize=10, color='#dc2626', ha='right', fontweight='bold',
            bbox=dict(boxstyle='round,pad=0.4', facecolor='#fef2f2', edgecolor='#ef4444'))

legend_elements = [Patch(facecolor='#3b82f6', label='Revenue'), Patch(facecolor='#22c55e', label='Prevention'),
                   Patch(facecolor='#f59e0b', label='Appraisal'), Patch(facecolor='#ef4444', label='Failure Costs')]
ax.legend(handles=legend_elements, loc='upper left', bbox_to_anchor=(0, -0.1), ncol=4, fontsize=9,
          facecolor='white', edgecolor='#d1d5db', labelcolor='#374151')

plt.tight_layout()
plt.subplots_adjust(bottom=0.15)
plt.show()