At the company, there is Lien A - a company specializing in the wholesale of building materials - every year, there is a plan of general revenue for the whole company and revenue for each division. In the current year, the revenue plan is set to increase by 20% compared to the previous year. The business situation of building materials in the current year faces many difficulties. The Board of Directors has asked the employees to find ways to achieve the planned revenue target assigned by the Board of Directors. Lien A's sales department is in charge of sales, in order to implement the policy of the Board of Directors, the sales department has promoted the recruitment of employees with sales experience and paid staff salaries partly based on revenue.. Lien A's sales method is mainly sold to agents. The company's website publishes quite detailed information about goods for sale as well as publishes a hotline for customers to reflect on the quality of goods. Sales manager is the person who receives information from the hotline and will report to the Deputy Director if that information is related to other departments in the company. The sales cycle goes like this: Processing orders. The company only sells to dealers. Agents (regardless of size ) can buy on credit up to 200 million dong and must deposit 200 million dong. When the agent has a need to buy goods, he will send an order to the sales department. If a dealer's order exceeds the maximum allowed amount, the order will be forwarded to the Sales Manager for review. In the past year, there were about 20 cases approved by the Sales Manager. After the order is approved, it will be sent to the warehouse. The warehouse keeper based on the approved orders to prepare the goods for delivery, then makes a release note based on the actual quantity of goods released from the warehouse. The delivery note is made in 3 copies, one is sent to the sales department, the other is sent to the accounting department to track the goods out of stock. Make an invoice Based on the delivery note, the sales department makes an invoice in 3 copies, 1 attached with the delivery note to send to the customer to receive the goods, 1 copy to the accounting department to record revenue, 1 copy to the department. business. Delivery to customers When receiving the goods, the customer will sign the invoice and the delivery note, a copy of the invoice is kept in the sales department. Revenue recognition Based on sales invoices, accountants record the value of goods sold in the sales journal. Accounts receivable from customers. Once a month, the chief accountant checks the reconciliation between the total amount and the details of receivables from customers. Customers with overdue balances of two months or more will be reminded by the debtors by phone and by email. The person in charge of debt checks the balance before reminding the customer. Last year, many agents still failed to pay their debts , the company has made provision for bad debts. Requirements: Please indicate : a) What are the advantages and disadvantages of the entity's control environment, control activities and information and communication systems? b) What measures are needed to minimize the weaknesses you detect?