What are the ethical issues raised by Tandy’s payment practices?

The ethical issue here is that Tandy misuses the opportunity given to him by the supplier and takes them for granted. The suppliers extend payment for 30 days yet Tandy goes beyond that for his selfish interest and probably without any explanations to the supplier. This is bridge of contract and it is very unethical.

What impact, if any, might these practices have on the firm’s supplier relationships? How serious would this impact be?

The impact this practice will have is that the suppliers may stop supplying because the delay in payment might be ruining their own business, and they may also inform other suppliers about the bad experience they had with Tandy. This would be a very big impact on the furniture-manufacturing firm, being a small business; it might start having difficulty in getting suppliers.

What changes in company culture, employee behavior, or relationships with other business partners may result from Tandy’s practices?

As said above, this may cause Tandy to find it difficult to find suppliers. To the employees, they may see the practice as normal and can adopt similar practice and it will automatically become the company’s culture.