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### Anatomy of The Three-Dimensional Charts of Time Scheduling

posted 6 Dec 2014, 12:47 by Oleksandr Tugayev
 As I said in the last blog post we’ll add to the two variables of deliverables and activities, a third variable: time. As a result, a three-dimensional chart was obtained. This chart was named as Deliverable-Activity-Time or DAT chart. In this chart every project task represents a line segment in three-dimensional space: deliverables-activities-time.  Two dimensions of this space are discrete: deliverables and activities, the third one: time, is continuous.  Deliverables –Time(DT) chart can be created as a section of the 3D task area by planes in parallel to coordinate plane deliverables of time.  Naturally, that section can be placed just in the points on the activities axis, where this discrete variable exists. Each plane will include the project tasks carried out at the certain stage of project lifecycle. Thus, all the project tasks will be located in the planes passing through the points at A axis, in which discrete variable activity exists. In other words, in each plane there will be Gantt chart, not for the whole project but only for its selected stage corresponding to A variable fixed value. This chart was named Delivery – Time (DT) chart. It can be interpreted as a set of timelines for each deliverable. Each line of this chart corresponds to a certain deliverable and contains timeline for this D.  Three-dimensional multi-layer DT charts can be looked through by layers.  Let’s have a look at all the layers simultaneously from this side, perpendicular to DT section plane.  As for me, I think it’s easier to work with a DT chart than with Gantt. For example, it’s much easier to have the whole project chart “at sight” and select the necessary layer or layers from it than to turn over multi-page Gantt charts. The user is free to choose each section separately, all sections together, or only some section groups. The choice is generally not limited and can be defined for each case individually. If a detailed multi-layer Timeline may seem to somebody too difficult to work with he or she can always look through separate layers of DT chart. There is also possibility to look through a DT chart as Gantt chart or bar diagramm, i.e. to connect all the layers sequentially.  The similar situation occurs if we consider sections which are parallel to another coordinate plane activity and time.  This chart was called Activity-Time (АТ) chart. Both above mentioned diagrams correspond to deliverables- and activities-oriented WBS correspondingly. As they are two-dimensional charts of one and the same three-dimensional chart we have the following advantage: having prepared DA matrix and DAT chart once we’ll be able to work simultaneously with both types of WBS: delivery-oriented and activity-oriented WBS. In this case there is no need to make the choice in the beginning when the WBS type for the project is defined.  As all those present know, this is the way we have to act while working with popular commercial software. Let’s have a look now at what we’ll get if we take a projection of our three-dimensional chart onto DA coordinate plane.  As it was mentioned earlier, the whole project scope is presented as DA matrix which can be interpreted as a PERT chart or backlog for whole project. It’s because the whole project scope is presented as a complete set of non-zero elements of this matrix. As it was mentioned earlier, the whole project scope is presented as DA matrix which can be interpreted as a network chart or backlog for whole project. It’s because the whole project scope is presented as a complete set of non-zero elements of this matrix. If for DA matrix setup we use not the whole project time, but, for instance, the term of one sprint, we’ll obtain respectively a sprint backlog when we separate time interval corresponding to single sprint. Originally posted 30th May 2011 by Oleksandr Tugayev