This study focuses on the importance of accounting and finance functions, duties, and roles in financial decision-making. It explores the computation and analysis of ratios in the context of Skanska PLC, a UK-based Construction and Engineering Corporation. The study highlights the significance of bookkeeping, treasury management, inventory management, cash flow management, investment management, financial reporting and analysis, strategic decision-making, budgeting processes, longer-term financing, tax management, risk management, and capital budgeting. The study also analyzes the ROCE, net profit margin, current ratio, and debtors collection period for Skanska PLC.