Time–distance diagram

Distance-time graphs are used to represent and planning of linear construction projects ( construction line ). Concrete examples are road, track construction, tunnel construction, pipeline construction, pipeline and bridge over. In some areas, such as track maintenance, is required by the builders for tender, notice of the construction project a distance-time graph. This is to ensure the quality of the offer and make planning mistakes early visible.

The main imaging effect of a time-distance diagram is the connection of the geography of the site with the timing. So shows a distance-time graph when and where and at what speed the individual tasks to be done. On the horizontal axis of the path portion is represented, while the time is shown on the vertical axis, as a rule. A task is shown as a line. This begins at a start - point (start - date and start -site ) and moves to the end point (end- date and end- site). The slope of the process thus corresponds to its velocity: A gentle slope is faster than strong inclination. Intersections of the lines in this case have to go on collisions and conflicts between operations. Such conflicts can not be seen ( bar chart ) in the classic Gantt chart.

For further illustration can be shown parallel to the distance axis a sketch of the construction site. This increases the intelligibility of individual transactions and networking / order in the action.

Spatial and temporal closures of certain sections within a building site area can be represented by a position-time graph (eg breeding areas of protected birds during the construction project ). When planning these limitations can then be identified and considered visually.

Differences and advantages compared to the Gantt chart

Gantt chart and network diagram are analytic as a path -time diagrams, but fail in the visual and operational technical connection between the project geography and the planned project schedule. Distance-time graphs increase the vividness of a project with spatial linear expansion enormous:

• They show the direct link to the map of the site and convey what is built and where.
• Spatially and temporally overlapping events can be easily detected.
• They convey a clear understanding of services by the inclination of the process line.
• They show the impact of changes on the timing and on the track.
• They show the philosophy / structure of the project workflow graphically.