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31 Jan 2017

LEGO Architecture meets BIM – Part 19: Sequencing Part 3


In the last two posts of the ‘LEGO Architecture meets BIM‘ series we have seen how we can visualise the building sequence with both GRAPHISOFT ARCHICAD and Solibri Model Checker. Both of the methods described rely on having some data related to the sequence. But of course in order to do this the model author needs to know the sequence of steps. Whilst this process is useful for early stage visualisation of a construction sequence it is less effective when managing real buildings to understand the detailed steps to erect a building. Therefore solutions have been developed by various vendors to produce more advanced approaches to construction sequencing. This typically involves using a model connected directly to a project programme. As this process involves a 3D model and adds time it is often referred to as 4D construction.

For the purposes of writing this blog, I have kindly been assisted by Pawel Krecz who is a Senior VDC Specialist at Synchro Ltd. Pawel has produced much of the text and animations in this piece so really the credit for the vast majority of this blog piece should go to him.

Of course one of the main reasons for us contacting Synchro was the fact it supports IFC as an open format. Again this piece shows how IFC can be used to benefit real life construction projects.


Image: The LEGO Villa Savoye model viewed in Synchro (click to enlarge)

Below Pawel takes us through some of the functionality and workflows available within Synchro. I should say from a personal perspective, this is just one tool and functionality and processes will of course vary from tool to tool. An OPEN BIM process should allow everyone to choose the right tool for their business needs. For some this may well be Synchro but as explained later a variety of tools exist to produce 4D sequences.

The aim of sharing some of the detail below is to help others understand the key concepts behind one particular 4D tool and show how even a LEGO model can apply the techniques that would be applied on real projects.

The post is pretty technical in nature and relates specifically to functionality of utilising IFC models in Synchro. So if as a reader you are less interested in the technical process of creating a 4D sequence within Synchro, I highly recommend watching the animations that are included further down in this blog piece, particularly the final one.

In many ways the concept of 4D is perfectly explained with LEGO. After all the instruction book for any LEGO set is basically a 4D sequence with each step having some time associated to construct the required blocks. Of course real projects are not normally as easily described in a nice instruction books but the process of constructing a building can learn many lessons from LEGO’s simplicity.

Synchro and other 4D tools

Synchro’s advanced integrated engine is intelligently linked to the 3D model, creating a visual time machine, providing reliable and fast access to data. Users can create baselines, analyse project visually, moving forward and backward in time, add resources, quickly make edits and optimise in a way that was never possible.

Alternatives to Synchro are: Navisworks Manage, Asta Powerproject BIM and Vico Office Suite.

IFC Settings

The first step in the process is to understand that like many BIM tools there are options available to control how and what is imported into the receiving software. In Synchro the Options dialog controls the import of Elements and Spaces.

000 IFC Settings

Image: IFC settings in Synchro’s Option dialogue (click to enlarge)

IFC Import

Synchro imports geometry, intelligent data and scheduling information (if included) from IFC files (versions: 2x, 2×2, 2×3 and 4).

Note: Synchro supports “ISO 10303-21:2002” IFC file text encoding.

001 Import IFC

Image: Import menu (click to enlarge)

IFC Import Options

During import, users control what elements are to be imported and how to process them. If the IFC file contains any user-defined properties (using IfcPropertySetDefinition), then these property values can also be imported by selecting the following options on the import dialog:

  • “Read properties of IFC elements”
  • “Read properties of IFC spaces”

002 Import options

Image: IFC import options (click to enlarge)

003 Import confirmation

Image: Successful import confirmation (note: warning messages are instructions to users to rectify some data) (click to enlarge)

The imported IFC model will be referenced in the Navigator>External Data panel and elements will be shown in the Resources list. All imported resources are organized into a 4-level hierarchy: File, Building, Floor and Element (elements which are not related to the building elements are placed at the top of this hierarchy).

Importing IFC Tasks

The “Create Tasks and Assignments for all IfcElements” option can also be used to enable the automatic creation of tasks and resource assignments within Synchro based upon the imported resources (as well as any IFC Task elements that may be in the file). Automatically created tasks are ordered according to location (floor), then by element type: roof, other elements, windows and door elements.

If the IFC Task descriptions contain a hierarchical task identifier (e.g ‘’) then this can be used to sort the tasks created within Synchro by enabling the “Read IfcTask’s Description as WBS number” option.

Importing IFC Spaces

When Spaces (IfcSpace) are imported, they are automatically created in Synchro as “Location” resources.

004 Post import 1

Image: IfcSpaces as processed by Synchro (click to enlarge)

Geometry and Data Check

The basic unit for import of the geometry information is the IfcElement (in this case the LEGO blocks). If these elements also have a 3D representation, then it is also imported by Synchro as a 3D resource. Users can find IFC object on the Resource list, 3D representations on the 3D Objects list and displayed as geometry in the 3D View windows.

004 Post import 2

Image: On selection, users can also check the data associated with the object (click to enlarge)

Intelligent Data

IFC (like any other BIM) contains geometry and intelligent data (attributes, parameters) associated with objects. Synchro imports BIM data and processes them as User Fields.

User Fields represent both: original information (imported from a source model) and user customised data (created in Synchro). Intelligent data can be used for a variety of different reasons (e.g. advanced filtering, colour coding, 4D auto-matching, etc.).

The imported LEGO model contains an extensive library of parameters. Some of them are extremely important and most useful during the creation of the 4D model (e.g. quantity, category, location etc.), some of them, not populated during the design stage, can now be rectified/modified in Synchro (e.g. “[COBie_Component]InstallationDate” parameter can use the ‘real’ date once the time schedule is created and installation date of this component is known).

005 Intelligent data

Image: Intelligent data associated with an IFC object (click to enlarge)

3D Filtering

A 3D Filter is used to hide / show elements in the 3D window based on:

  • selection (also known as ‘3D sets’)
  • any system or user-defined criteria (utilising intelligent data).

With just a few ‘smart’ parameters users can easily find specific content, show or hide objects or colour-code them temporarily overwriting the original colours of 3D objects. This has significant importance when working with large models with thousands of objects.

A few examples of the functionality are shown below.

006 3D Filters unfiltered

Image: The unfiltered LEGO model with all 3D objects visible (click to enlarge)

007 3D Filters orginal colours

Image: Objects filtered by a single criteria to show only LEGO bricks with the Name ‘Plate 1X2’ (click to enlarge)

008 3D Filters temp colours

Image: Additional settings for the same filter allow the colours to be temporarily changed for the filtered objects and to show the ‘hidden’ ones as transparent (click to enlarge)

009 3D Filters colour

Image: Another example of intelligent filtering. This time the criteria is a colour of the objects, coded in the parameter (i.e. Colour_Green) (click to enlarge)

010 3D Filters combo

Image: Applying the two different filters at the same time will create a funnel effect – now both criteria from the example filters above are met (i.e. ‘Plate 1X2’ AND ‘Colour_Green’) (click to enlarge)

This data visualisation in Synchro is similar to functionality demonstrated in an earlier post in this series – see blog post on Visualisation of model data.

Time Schedule Creation

Time schedule (in the UK referred to as ‘programme’) is a fundamental part of 4D modeling. Without schedule data, there is no ‘real’ 4D BIM. Only by associating 3D Resources with schedule Tasks one can build the 4D model. This association is also a basis for further information modeling (e.g. 5D, 6D).

In Synchro, users can create time schedules using the following methods:

  • Import / Synchronise from external source (planning software: MS Project, Primavera or Asta),
  • Create task list in Excel spreadsheet and copy to Synchro (further data conditioning is required: e.g. calendars, relationships, resource assignments, cost etc.),
  • Creating tasks and relationships directly in Synchro.

Synchro is an independent planning platform (PRO and Scheduler versions), therefore a time schedule can be build and managed within Synchro alone. This approach doesn’t require the use of external (additional) planning software.

Calendars, tasks, constraints and logic relationships can be build and structured in Synchro by:

  • manual input,
  • using model-based techniques.

Manual input is in essence, the same method known from a planning process. There is no major difference in creating schedule in Synchro and other planning software (e.g. Primavera, MS Project).

Also, the procedure and the outcomes are the same: create & save the baseline > progress & variances monitoring > track & actualise the schedule > control & report > re-plan (if required).

The biggest functional advantage of Synchro, is its association with 3D data, which is then turned into 4D data in the BIM process.

The model-based approach allows linking of tasks and 3D resources automatically (or building of tasks from 3D resources), extract and visualise the progress of activities, transfer and calculate data across / between resources and tasks. This is known as ‘4D Linking’ or ‘4D Modeling’.

Digital representation of 3D linked to a schedule creates a basis for construction simulations and visualisations (also known as ‘animations’).

The most efficient way to create a schedule in Synchro is to build it from 3D resources. This is also the most professional and elegant method.

The imported IFC model contains (our beloved) LEGO bricks geometry and intelligent data. The scope of data is extensive – 576 unique parameters created in the BIM authoring process. Each element (resource) is described so well, that even unexperienced planner will have no issues in finding relevant (specific) scope.

One resource parameter is a key to automated tasks creation – ‘IfcPresentationLayerAssignment’. It holds the sequence of building, which follows the original LEGO instructions. (Note from Rob: this was done purely for this project but ARCHICAD could have used a specific property set up for sequencing/phasing to create this data for 4D purposes).

An additional resource parameter has been created in Synchro to further detail the sequence of the multiple elements (bricks), which are built in the same step.

The example below shows 10 elements in Step 12, so a more detailed sequence is required, as the builder can only do one brick at the time (non-concurrent relationship). In a real project scenario, the schedule would contain both concurrent and non-concurrent work.

011 Sequence

Image: The LEGO elements to be built in Step 12 (click to enlarge)

With sequence parameters, planner can sort all the resource objects by the parameter values (which describe ‘steps’), select them and with a few mouse clicks, create the entire schedule. Synchro not only will create a tasks list but it will also automatically:

  • assign the resources with the default work profile (‘Install’),
  • create a logic relationship network (based on ‘sequence parameter’ and resource selection order; by default – Finish to Start links)

All the default settings, relationships and work profiles can be changed by the user at any point.

Now the schedule tasks only require proper durations – those can be left alone (the default will apply), input / modified manually or calculated automatically from different resource parameters (e.g. quantity data).

012 Task creation

Image: Creation of resources in a few mouse clicks (click to enlarge)

That completes the process!

The simulation is now displayed in the 3D View window. Moving Focus Time line (Synchro feature) across the schedule timeline will display, in real-time, the results of ‘4D Linking’. Project team now has the ability to visually test the sequence, check the correctness, test different options and apply changes to the schedule logic until it’s sound. Early detection of problems (risks) is happening at this stage and the benefit is obvious.

013 Focus time

Image: Focus Time Line before the project, during and at the end (click to enlarge)

001 Focus time

Image: Animated GIF showing the above (click to open in a new window)

Work Profiles

Different types of work can be simulated with the use of work profiles, which are called ‘Resource Appearance Profiles’ in Synchro. They provide an indication of how a particular resource is used in a project, and allows the appearance (display, colour and transparency) of the resource to be changed as the resource is utilised over time.

There are a 4 pre-defined System Profiles, which will be used by default when assigning to tasks. Users can also create their own profiles.

014 System RAPs

Image: System profiles used to simulate different type of work (click to enlarge)

015 Work Profiles

Image: User customised profiles (can be built from the System profiles) (click to enlarge)

Auto Matching

When the schedule is imported into Synchro from an external source, model-based planning is difficult and creating tasks does not make any sense. In that scenario, users are facing the time and effort consuming process, in which 4D links are produced by searching for matching scope (comparing Resource and Task lists) and creating relationships manually.

However, a Synchro tool called ‘Auto Matching’ can help users to find matching resource / task pairs and apply links in an automated manner. This tool also utilises Task and Resource parameters, so the existence of intelligent data is essential.

This example (and others) shows how different tools can utilise the same data, which is the real benefit of a parametrically-rich BIM.

016 Automatching

Image: Auto-Matching tool in Synchro (click to enlarge)

Basic Animation

The automatic simulation in the3D View window is ‘linear’ and depends purely on the schedule timeline. Users can play and adjust the speed of Focus Time based simulations by accessing Play toolbar from the Ribbon menu.

017 Play

Image: Play panel in Synchro (click to enlarge)

Another way to play simulation is to create custom Animations and save them within a Synchro project (those can also be exported to AVI or embedded in FBX format). Users can create and store unlimited number of Animations.

The creation process requires users to add and manage three types of Keyframes in the Animation Editor.

Keyframes define the:

  • 3D Viewpoint (camera-angle, position and zoom),
  • Focus Time (schedule contents),
  • Events (3D grids, 3D annotations etc.)

of the 3D Windows at any given point in time within the Animation.

The Animation Editor Window is initially composed of Camera, Focus Time, and Event channels that can be animated, a scalable Time Line depicting time segments, and a Focus Time Marker.

018 Animation

Image: Animation Editor in Synchro allows users to create and modify customised animations and export them to AVI format (click to enlarge)

Users will develop their own techniques for creating animations, but one possible workflow for creating an animation is as follows:

  • Define the start and finish Focus Times,
  • Define the starting 3D view (by manually adjusting the 3D view or using previously saved 3D Viewpoints)
  • Compressing slow periods of time / adding more Focus Time Keyframes (if there are long periods in the project when nothing happens in the 3D window, user may wish to shrink that time in the animation).
  • Updating 3D View / adding more Camera Keyframes (to better view / suit what is happening in the project, e.g. work has progressed to a different location in the site),
  • Adding 3D Notations / add Event Keyframes (this is a new feature in Synchro),
  • Review and further edit the animation.

Once the Animation is created, users can export its content to AVI video format. On ‘Export to AVI’ additional content can be added on top of 3D output:

  • Focus Time indicator,
  • Schedule Timeline,
  • 3D object list / legend,
  • Gantt chart / list of tasks,
  • Images (also transparent),
  • Textual frames (fixed text or dynamic information: e.g. cost, name of simulated tasks, etc.)

019 Export avi 1

Image: Export to AVI panel (click to enlarge)

Animations can also be exported as a series of images. The ‘time slice’ (snapshot of the project) is controlled by generating automatic timeline in Animation Editor (e.g. every day / 1 frame) or by using FPS parameter (frames per animation second).

020 Export avi 2

Image: Export options (click to enlarge)

021 Timeline generation

Image: Timeline generator automates the creation of ‘time slices’ / snapshots of the project (click to enlarge)

022 Series of pics

Image: Series of images exported from Synchro (click to enlarge)


Animation: Basic animation created by Synchro of the sequence without the programme (click to open in full screen)

Further basic animations of the individual views from the above animation:


Animation: Top view (click to open in full screen)


Animation: Front view (click to open in full screen)


Animation: Left view (click to open in full screen)


Animation: Right view (click to open in full screen)

3D Paths

A 3D Path represents a route through the 3D scene that may be taken by a 3D resource, which is utilised on a Task. This is an effective mechanism for modelling motion related activities (e.g. movement and rotation of equipment) and also camera movement (in Animation Editor, camera viewpoint can travel along the selected path, when Interpolation Type is set 3D Path).

Use of 3D paths and additional logistics models imported to Synchro enables more sophisticated animations, which would better reflect what is happening on site during the construction. Movement of objects through the restricted spaces for example, can be dynamically detected in Synchro by the 4D clash detection tool called “Spatial Coordination”.

3D paths can be drawn in Synchro manually or converted from CAD geometry (polylines, circles, arcs, etc.).

023 3D Paths

Image: 3D Paths control the movement of objects and camera viewpoints (click to enlarge)

Advanced Animation

Advanced animation often better ‘describes’ what is happening on site during construction. By adding additional elements to the master model, one can increase the value of the modelling by simulating temporary works, workspaces, risk and safety issues, logistics and site environment.

The example animation below shows how the visual value of the output is building up by adding just two new elements – crane model and 3D paths.


Animation: Animation of the model building up with the sequence with the project programme in context (click to open in full screen)

Note: this animation has been reduced in quality for use on the blog.

This video shows how the sequence can be developed exactly as it will be built. These follow the LEGO instructions so you will see how some parts are constructed separately to the model and then connected once complete. You will also see how the first floor is built as a separate construction and then placed onto the lower floors after being assembled.


Synchronise From” function in Synchro allows users to update data when IFC (or other models) are revised. Therefore, it is important to keep the original import references in Synchro Navigator>External Data panel – from there users can access synchronisation function (right click on the source).

024 Sync from 1

Image: Every imported model is references in External Data panel in Synchro (click to enlarge)

When “Synchronisation From” (updated revision of the model) is performed, Synchro confirms the operation with the dialog similar to ‘import confirmation’.

025 Sync from 2

Image: Successful synchronisation confirmation  (click to enlarge)

Synchro allows to update an existing IFC file with schedule-related data (4D associated information) from a 4D project directly to IFC with “Synchronise TO” function.

To update an existing IFC file, the following steps are taken:

  • In the Navigator->External Data panel, select the previously imported IFC model
  • Right-Click > Synchronise To … (press the Browse… button to select a different target file if required)
  • Press Next > to display the IFC Synchronise options dialog and process further.

026 Sync TO

Image: “Synchronise To” options (click to enlarge)

Synchro writes 4D BIM data into the original IFC model, filling up the ‘blanks’ – Tasks, Links, Calendars, Resource assignments and adding new parameters, created in the process. The initial 3D IFC model becomes 4D IFC model and the original IFC file is backed up by “Synchronisation To” operation.

027 4D IFC

Image: New IFC model created by Synchro, now 4D BIM (click to enlarge)

Now the model can be shared as a 4D IFC. Unfortunately, only limited number of IFC-ready software can read the 4D BIM data.


We have seen in the last three posts that there are a variety of ways of creating a building sequence. Some of these methods are more primitive than others but all aim to explain the construction sequence to the viewer. There is no right or wrong way to do BIM but more advanced processes mean that more intelligent decision making can be made.

With a true 4D process (linking a programme to the model) the benefit of optimising the programme comes into play and this means that the model becomes a critical part of delivering projects effectively and of course helping to eliminate delays in handing over assets to clients.

Ultimately of course, time is money! In the next few posts we will look at the quantification and costing aspect of BIM.

Finally I would like to thank Pawel Krecz once again for helping to create this blog piece. Like a lot of things in this series I have added more knowledge to our overall BIM understanding and Pawel has played a big part in advancing our understanding of 4D processes.

Rob Jackson, Associate Director, Bond Bryan Digital



Pawel Krecz, Senior VDC Specialist, Synchro Ltd


More about Synchro

Synchro Software was born from a passion to bring improvement to the construction industry. Our 4D BIM visual planning and scheduling software is purpose built for the complexities of the construction industry to resolve the inefficiencies in its processes, so that projects can be reliably delivered better, faster and cheaper.

Industry leaders are achieving new performance standards through crystal clear communication, highly engaged cooperation and reliable and validated plans – because the most effective way to plan a project is visually.

Improve the safety, quality and reliability of your projects through our 4D Scheduling Time Machine.

Synchro Products:

Synchro Pro

Synchro Pro

See your project being built virtually in real time, edit and optimise in high accuracy / low risk visual environment.

Synchro Workgroup Project

Synchro Workgroup Project

Your entire team can access project updates in real time from the access controlled master file in Synchro Workgroup Project.

Synchro Site

Synchro Site

View the 4D BIM, track progress and resource statuses from the field directly from your iPad, sync updates to your 4D schedule with a finger tap.

Synchro Scheduler

Synchro Scheduler

Available free upon request Synchro Scheduler is a traditional 2D Gantt chart project planning and scheduling software with an advanced CPM engine.

Synchro Open Viewer

Synchro Open Viewer

Open 4D project files created by others in Synchro PRO. Give your entire team unparalleled clarity to thoroughly understand plans and schedules so team members can better execute, quickly respond to unexpected changes and create value for their organizations and stakeholders.

Web: https://synchroltd.com

Twitter: @Synchro_Ltd

Contact for Customer Engagement: Tom.Dempsey@synchroltd.com

Contact for Synchro Project Delivery: Pawel.Krecz@synchroltd.com

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