A business casual crop top and mini skirt set can be a stylish and contemporary outfit option for certain professional settings. However, it's essential to consider the specific workplace's dress code and the nature of your job, as business casual can vary from one organization to another. Here are some points to keep in mind:

Crop Top: When selecting a crop top for a business casual environment, opt for a top that isn't overly revealing. Choose one with a modest length that doesn't expose too much skin, especially around the midriff. Look for well-tailored options in neutral or classic colors.
Mini Skirt: A mini skirt in a business casual context should be of an appropriate length. It should fall at or slightly above the knee. Avoid skirts that are excessively short or tight. Neutral or subdued colors work well in professional settings.
Material: Choose high-quality, professional materials such as wool, cotton, or other non-sheer fabrics. This will give your outfit a more polished appearance.
Fit: Ensure that both the crop top and mini skirt fit you well. They should be neither too tight nor too loose, providing a neat and comfortable look.
Accessories: To maintain a business-like appearance, accessorize thoughtfully. You can add a blazer, a statement belt, and classic, closed-toe shoes to complete the look.
Colors and Patterns: Stick to neutral or muted colors for a professional appearance. Avoid overly bright or flashy patterns, as they may not be suitable for a business environment.
Grooming: Pay attention to your grooming. Well-kept hair, minimal and tasteful makeup, and clean, polished shoes are all essential to creating a professional image.

Remember, the appropriateness of a crop top and mini skirt set in a business casual setting can vary widely based on the culture and industry of your workplace. It's crucial to consider your company's dress code policy and the expectations of your specific role. When in doubt, it's generally safer to opt for more traditional business attire to avoid any potential issues.