Powersys is an electricity distribution company based in a large capital city. Its business is to manage the electricity assets, including poles, wires, and other equipment, that are used to deliver electricity to more than 500,000 retail and business customers in the city. Pole, wire, and substation maintenance and improvements are a large part of the company's operations, and teams of highly trained technicians are used for both planned work and emergency response activities. Emergency response is required when storms or fires bring down power lines, the power must be turned off at the direction of police, or the electricity supply fails for any reason.

Each team has several vehicles (vans and trucks) and uses additional heavy equipment, such as cherry pickers, cranes, and diggers, as required. Each vehicle carries a core set of specialized parts and tools, and additional items are obtained as required from storage, which is located in a large warehouse in the northern suburbs. The warehouse is staffed on a 24-hour basis to assist night maintenance (designed to minimize disruption to business customers) and emergency response.

What internal controls over parts, equipment and labour could help Powersys avoid potential problems?( select all right answer which is more than 1)

i)Scheduling of regular maintenance on equipment required for emergency response

ii)Assign the responsibility for maintaining communication systems with emergency services to recently hired technicians

iii)Have the HR department oversees policies and procedures for staff training to ensure sufficient staff have the required skills

iv)Staff schedules and roster approved by senior management

v)Maintain security systems and assign responsibility for a staff member to coordinate with emergency response teams

v)Make HR department aware of staffing requirements for emergency response