In addition to using the spread tool, you can click on a cell and input a figure manually into a cell. The remaining amount left assignable tells you what amount has been inputted in front of the cell and what is left.
We advise you to work your way from left to right when manually adjusting each cell. For example, if you spread the Build Costs (£100,000) between Month 2 and Month 5 with a straight line distribution, the amount for each month will be £25,000 (25% of the Build Costs).
If the start month actually incurs a larger portion of the Build Costs, you can manually input e.g. £40,000 on Month 2. Then, the three remaining months will be automatically adjusted to £20,000.
Now, if you manually input e.g. £30,000 on Month 4, the amount of Month 2 and Month 3 will be unchanged. The cell on the right (Month 5) will be automatically adjusted to £10,000, not to exceed the total Build Costs (£100,000). The same goes for an S-curve distributed cashflow. It is designed to avoid mistakes from manual inputs.