ZEMCH 2015 - International Conference Proceedings | Page 290

Discussion
The study developed in Phase 1A was important to explore 4D modeling and simulation, especially when presenting the retrofit planning process to the site manager and to the foreman. Furthermore, this stage reinforced the needed of creating what-if scenarios in order to minimize
disruption for end users.
Currently, the retrofit execution plan on the S-IMPLER is performed by using stick notes on a
board. This is relatively fast and straight-forward, but it can hide some execution issues, bringing
possible rework and increased costs during the project. The retrofit execution plan requires the
support of management and visualization tools to assist in carrying out the work. So there is a
great potential for use of BIM 4D tool in this project. Although a visual device containing screenshots has been used on site in Phase 1A, its applicability has not achieved its central objective.
A new attempt will be made in Phase 1B, as previous studies have proven that in new buildings
the use of visual devices facilitates the application of the model 4D on sites (Sacks; Treckmann;
Rozenfeld 2009; Bortolini 2015).
There are opportunities in terms of training in 4D modelling and simulation, as the site manager
and foreman had limited knowledge about the topic. It was agreed with participants that it is
more difficult to visualize the 4D simulation in retrofit projects than in new construction because
some elements are already existing parts of the building.
The study developed in Cycle 1 was important to understand what disruption for tenants is, and
how the use of 4D BIM models can minimize it. Some studies point to the difficulty to conduct
refurbishment in buildings where users remain in the site during works, but very few of them indicate what are the disruptions that can be found in these works. Thus, it was important to create
a set of categories of disruption based on literature review.
Although the method was devised, steps 1 to 7 have been partially used. So far, the critical points
of the method are: to identify and capture clients’ requirements, to assess the influence of a dwelling’s owner and/or a dwelling’s user as main clients, and to define the construction technology
without client’s support. Consequently, it is necessary to collect more information with external
suppliers in order to fine tune the tasks sequencing.

Conclusion
This paper described how 4D models are explored in the improvement of construction planning,
particularly in the reduction of occupiers’ disruption in retrofit projects. The findings presented in
this paper are part of an ongoing study.
First main finding of this paper is the identification and characterization of disruption for tenants
when the retrofit works are carried out. It is highlighted the need to identify and to characterize
disruption for tenants using three sources of evidence: literature review, stakeholders’ perspective, and tenant’s point of view. Thus, a survey assessing tenants’ perception about disruption can
gather relevant inputs to refine and build what-if scenarios. An accurate definition of disruption
would enable the creation of alternatives for executing works on site.
Second main finding is the method for creating what-if scenarios using BIM 4D. This proposed

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ZEMCH 2015 | International Conference | Bari - Lecce, Italy