By virtue of being a repository for tank inventory and receipt\delivery shipments, OAS is able to provide a site-wide mass balance, reflecting an overall position of what has moved in and out through the fence. This is supplemented by a range of features to underpin the activities and analysis of the oil accounting group.

As further support, OAS includes the following functions:-

• Tank inventory, qualities, material duties, compositions
  
  
• Adjustments and other postings to supplement the foundation of opening and closing stocks, receipt and delivery shipments in forming a mass balance across a chosen period, whether daily weekly, monthly or ad-hoc
  
  
• Shipments in progress features to help the oil accountant assess what interim postings should be counted in a period if they are operations in progress at period boundary
  
  
• Voyage Analysis and summary statistics to include ship and shore figures at load and discharge ports for analysis from BoL to Outturn and local ship\shore comparison
  
  
• Vessel Experience Factor calculation
  
  
• Duty Accounting
  
  
• Mass Balance approval and submission to finance system