Business System:
A business system refers to a set of interconnected elements and processes that work together to achieve a specific goal or objective within an organization. It encompasses various activities, resources, technologies, and people that are involved in the operation and management of a business.

Sub-systems of a Business System:
1. Operational Sub-system: This sub-system deals with the day-to-day activities and processes that are essential for the functioning of the business. It includes production, marketing, sales, customer service, inventory management, and other operational aspects.

2. Financial Sub-system: The financial sub-system focuses on managing the financial resources of the business. It involves activities such as budgeting, accounting, financial planning, cash flow management, and financial reporting.

3. Human Resources Sub-system: This sub-system is responsible for managing the organization's workforce. It includes activities like recruitment, hiring, training, performance management, employee benefits, and employee relations.

4. Information Technology Sub-system: The IT sub-system handles the technology infrastructure and systems that support the business operations. It involves managing hardware, software, networks, databases, and other IT resources.

5. Marketing Sub-system: The marketing sub-system focuses on promoting and selling the company's products or services. It includes market research, advertising, branding, pricing, distribution, and customer relationship management.

6. Supply Chain Sub-system: This sub-system manages the flow of goods, services, and information from suppliers to customers. It involves procurement, logistics, inventory management, supplier relationships, and demand forecasting.

Interaction between Sub-systems:
The sub-systems of a business system are interconnected and interact with each other to achieve the overall goals of the organization. Here are some examples of how different sub-systems interact:

1. The operational sub-system interacts with the financial sub-system by providing data on sales, production costs, and expenses, which are crucial for financial planning and budgeting.

2. The human resources sub-system interacts with the operational sub-system by providing trained and skilled employees to carry out the day-to-day activities of the business.

3. The information technology sub-system interacts with all other sub-systems by providing technology solutions and infrastructure to support their operations. For example, it enables the marketing sub-system to conduct online advertising campaigns and the supply chain sub-system to track inventory levels.

4. The marketing sub-system interacts with the supply chain sub-system by providing information on customer demand and market trends, which helps in inventory planning and logistics management.

5. The financial sub-system interacts with the supply chain sub-system by managing payments to suppliers, tracking costs, and ensuring efficient use of financial resources in the supply chain processes.

In summary, the different sub-systems of a business system work together and rely on each other's inputs and outputs to ensure the efficient functioning and success of the organization.