Heterorhythmic flow.
Some processes have the same rhythms, while others have different ones. The lines on the graph from the first category will be parallel. The rest will be drawn at individual angles of inclination. The smaller the angle of inclination of the line, the longer the work on each section.
Irregular flow.
The duration of each individual type of work is individual and does not coincide with others. In the graph, the flow line has a broken appearance.
Based on its essence, the method of flow construction and the use of cyclograms are typical for linear-extended construction projects (roads, pipelines, power lines) and projects with typical components (multi-apartment residential buildings, office complexes, warehouses).
Let's consider the construction of a cyclogram for a road construction project. The project schedule, on the basis of which the cyclogram is constructed, is presented below.
Stream construction
Road works calendar and network schedule
Based on this schedule, a cyclogram was formed by pickets. The dotted lines show the target plan, and the solid lines show the current project schedule:
Stream construction
In the figure, you can see how the time scale is located at the top, and on the left are listed pickets with the dimensions of each. The inclined lines represent teams of workers by types of work, the inscriptions on the straight lines indicate the volume of work on the site. It is also clear that the work on each site is carried out sequentially and almost without breaks. At the same time, each individual flow maintains an equal pace, but all flows do not coincide in rhythm. That is, the cyclogram shows an example of heterorhythmic flows.
The following image shows a construction cyclogram for a business center. It shows that the work on installing the curtain wall (bright pink curve) initially coincides with the flow of ceiling finishing, but with the start of work on the third floor, it changes its pace and soon intersects the work schedule for installing stained glass windows. Such an event is an error that contradicts the principle of constructing cyclograms. Therefore, work planning requires adjustments from the person responsible for this task.
Stream construction
Cyclogram with a plotting error
Irregular workflows can be most often observed when the construction site is atypical and the work areas have different volumes of work. The following image shows a work cycle diagram for industrial construction sites. The durations of individual works differ for flows 1, 2, 3 and 4. This difference is due to the individuality of each object. Also, at all objects except the third, work is performed with downtime, which may require optimization of the movement of labor.
Stream construction
Cyclogram with arrhythmic flows
Planning work resources using cycle diagrams
The figure shows a schedule for installing an outdoor lighting line along a highway. Here, the set of works is typical for each picket, and the volumes of work at each picket are the same. Let's imagine that you need to plan a uniform workload for work teams to perform work at the site. Let's analyze this problem using the example of installing an outdoor lighting line. In this case, the set of works will be typical for each section, and the volumes of work at each picket are the same. First, let's build a calendar-network schedule for performing work.
Stream construction
If each type of work is performed by a specialized team of workers, then a total of 8 teams will be required. An example of a cyclogram under such conditions is shown in the image below:
Stream construction
After drawing up the cyclogram, it immediately becomes clear that each of the flows has different rates, and half of them have downtime between transitions from one picket to another. It is obvious that forming teams for individual types of work will not be the most effective solution. Therefore, let us consider the option when one separate team performs its set of works on one picket (PC). Then PC1 and PC2 will be performed by one team sequentially, and PC3 and PC4 will also be performed, but by another team.
Another possible variant of constructing a cyclogram is based on the distribution of work groups among teams at each picket. In this case, 8 types of work will be distributed among three teams: Group 1 — work 2.1, 2.2, 2.3; Group 2 — work 2.4 and 2.5; Group 3 — 2.6, 2.7 and 2.8. Then, after the completion of work group No. 1 at PC1, work group No. 1 starts at PC2, etc.
The image below clearly shows each of the described workforce planning scenarios in comparison. In the second option, the construction flows are rhythmic, in the third, only the first two flows are rhythmic.