... expended, the accuracy of estimates is a key factor in achieving project success Historical data, even from parts of previous projects, can be valuable as an initial guide Analysis of the actual proposed ... preparation of the key stage cost data and the project budget Accuracy: ± 5% Sources of data As the duration of each key stage is the real time it will take to complete the work this is usually the ... easy to read and understand Planning your project l 149 ANALYSING THE LOGIC DIAGRAM The analysis of the diagram is a simple logical process extending the initial calculation you made earlier to...