A well-researched and conscientiously prepared business case can definitely contribute to the successful outcome of any business. The requirement for this detailed business case and project plan stems from the business failure of the Yang sing hotel. As per the requirement of the new investment company, this report has been prepared for the successful relaunching of new Yang sing hotel. In order to identify the possible causes of failure of the yang sing hotel, a detailed literature review of the theoretical concepts of business case formation & project plan has been performed. The major issues identified were inaccurate formation of business case and project plan; imprecise estimation of cost and time; adoption of unsuitable project management methodology leading to project delay with cost overrun. The business case was prepared by first surveying the building to identify major work packages and stake holders. Time required and cost were estimated accordingly, leading to the development of budget plan with an amount of £6,343,000. A seven- year financial plan with total net operating profit of £8,987,452 while assuming the room rate to be in the range of £185-£225 with an occupancy rate of 75%-85% was developed to analyse business undertaking justification & cost/benefits evaluation. The following results are obtained by application of benefit realization formulae: By evaluating through bank deposit with 1.5 % of interest rate it will yield £7,009,015 within seven years, Pay back method requires 6.6 years of time period to cancel invested amount, and by discounted cash flow we obtain a result of £44,214 which is ≥ 0. This indicates that the project is viable and consequently, it would be profitable to proceed with the investment for relaunch of New Yang sing hotel project. The next vital step was the development of project plan & project management for new Yang sing hotel. The approach of lean-agile project management methodology is most suited for this type of project. Lastly, possible success/ failure factors for this project and considerations concerning future operation have been discussed.