Although it is possible to use project management tools manually, there are many computer software implementations of the methodolo gies. It is also possible to use standard spreadsheet programs for some of the applications such as the preparation of Gantt tables and charts. Gantt tables and charts are used to detail the planned start and comple tion dates of the specific task identified in the translation of experimen tal intentions discussed in section 1.2. A simple example of a Gantt table and an incomplete chart is presented in Figure 6.1.1. The figure depicts the planned preparations for an imagined field test of a new seed drill. There are three separate strands in the preparations. The first involves the preparation of the drill, the second the arrangements for selecting and gaining access to the chosen test sites, and the third the supply and preparation of seeds and fertilizer. It should be noted that some tasks cannot be started before others have been completed, and these dependencies are noted in the 'Predecessors' column of the table and by the arrows linking bars on the chart. The dependencies result from physical constraints. For example, it is not possible to buy the seed and fertilizer before the requirements of the site have been assessed.