Time analysis in Navisworks and Microsoft Project

Figure 127. Import of 3D model from Revit (Navisworks)

As it can be seen, Revit and Navisworks presents a perfect interoperability. This is expected as both software are part of Autodesk family. It’s important to mention that the time analysis process can be performed completely in Navisworks. However, as it will be shown during the thesis, Microsoft Project is a software that allows to consider all different aspects of the project management. Then, the process continues by recognizing from the 3D architectural model, all different elements of the structure as it’s shown next.

Figure 128. Elements of 3D model (Navisworks)

Once all elements are recognized and it’s intended construction sequence is applied, it can be created the time liner of the project as shown in the following figure.

Figure 129. Time Liner of pedestrian bridge project (Navisworks)

As it can be seen, the use of Navisworks with the 3D model from Revit, allows to create almost directly a time liner of the project. Additionally, as it’s shown in the upper right part of the last figure, this time liner can be exported to a MS Project file. Representing also a good interoperability between these two different tools even if they are not from the same family of software. The CSV file imported from Navisworks, is open from Microsoft Project as follows.

Figure 130. Import process from Navisworks (Microsoft Project)

Figure 131. Activities imported from Navisworks (Microsoft Project)

As it can be seen, the activities correspond only to elements of the 3D model. However, it’s important to mention that the time analysis requires a more precise information about the entire construction process. Then, in order to create a proper project management, it will be necessary to add all activities that were descripted before and are needed for the case study.

Additionally, it’s needed to configure the calendar that will be followed for the construction works. For the case study, is decided to follow a working calendar of 8 hours for each day of week (Monday to Friday), as is shown in the next figure.

Figure 132. Working calendar for pedestrian bridge project – Microsoft project

Now, it’s needed to use all activities or works for the construction of the pedestrian bridge that were previously described. Additionally, it’s necessary to define the importance of each activity, this means that the activities and sub activities must be differentiated, allowing to organize the project works hierarchically. These main activities and sub activities are listed in Microsoft Project as follows.

Figure 133. Definition of main activities and sub activities - Microsoft Project

As it can be seen, this procedure that was performed allows also to organize the project and for instance, will help to summarize the different main activities. Once the activities are completely defined and organized, it can be introduced the duration of each construction work of the pedestrian bridge. The duration of the activities is chosen considering the difficulties and lack of uses of many tools or machinery that can be used in a normal construction site, however, the durations are also chosen depending on the necessity to occupy, utilize or rent several equipment’s that are necessary, then, an increment on duration of activities and especially on the ones that are considered as critical ones will increase also the costs of the entire project.

This critical path will be analyzed subsequently when results from time analysis are obtained.

Thus, in the following figure are shown the activities with their respective durations.

Figure 134. Duration of activities in Microsoft project

The assignment of durations to the constructions works will not bring a proper time estimate of the entire project, this is because it’s needed to introduce also the path that must follow each activity, meaning that each activity must be preceded from another one. This decision is completely dependent on the criteria of the project manager. Microsoft project allows to work with a tool that is called predecessor, which works attaching a specific activity to another one and allowing to start or finish this activity depending on the command that is introduced. There are basically four types of connection to create a work schedule:

- End - Start (FC): The dependent activity cannot begin until the dependent activity does not it has been completed.

- Start – Start (CC): The dependent activity cannot begin until the dependent activity does not has begun. The dependent business can start at any time after the start of the business from which it depends on.

- End - End (FF): The dependent activity cannot be completed until the activity from which depends has not been completed or the dependent activity can be completed at any time after the completion of the activity on which it depends.

- Start - End (CF): The dependent activity cannot be completed until the activity from which it depends has not begun or the dependent activity can be completed at any time after the start of the activity on which it depends.

The definition of the dependency on activities will also give the Gantt Diagram which is commonly used in project management to show activities (tasks or events) displayed against time. On the left of the following figure, it will be presented the list of the activities and along the top is a suitable time scale. A bar is used to symbolize each activity, and the position and length of the bar correspond to the activity's beginning, middle, and finish dates.

Figure 135. Gantt diagram - Microsoft Project

The Gannt diagram allows to see what the various activities are, when each activity begins and ends, how long each activity is scheduled to last, where activities overlap with other activities and finally, the start and end date of the whole project. With this final step, the time analysis is completed and can be analyzed.