Yapı bilgi modellemesi (5D) ile maliyet yönetiminin avantaj ve dezavantajlarının tespiti
Determining advantages and disadvantages of 5D BIM cost management
Yazar: FARUK GÜLERSES
Danışman: DOÇ. DR. ESİN ERGEN PEHLEVAN
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / İnşaat Mühendisliği Ana Bilim Dalı / Yapı İşletmesi Bilim Dalı
Derece: Yüksek Lisans, 2018
Konu: İnşaat Mühendisliği = Civil Engineering
Dizin: Bilgisayar destekli modelleme = Computer aided modelling ; Bilgisayar destekli planlama = Computer aided planning ; Bina bilgisi = Building information ; Bina yapımı = Building construction ; İnşaat yönetimi = Construction management

Özet:
İnşaat sektöründe verimlilik değerlerinin düşük olduğu, bunun sonucu olarak da süre ve maliyet kayıplarının yaşandığı uzun yıllardır üzerinde çalışılan ve çözüm üretilmeye çalışılan bir konudur. Bunun en önemli nedenlerinden biri inşaat projelerinde konsept tasarım aşamasından kabul süreçlerine kadar farklı disiplinlerin bir arada koordineli bir şekilde çalışmak zorunda olmasıdır. Oluşturulmaya çalışılan koordinasyon ve uyum ortamının yanında projelerin doğası gereği kaçınılmaz olan değişim talepleri de yönetimde komplekslik derecesini oldukça artırmaktadır. Bu kaos ortamını ve muhtemel krizleri yönetmek için yeni yöntemler geliştirmek inşaat profesyonelleri ve akademisyenler için önemli bir hedef haline gelmiştir. 
Bu doğrultuda yapılan çalışmaların neticesinde geliştirilen en katma değerli yaklaşım kuşkusuz yapı bilgi modellemesi (BIM - Building Information Modelling) kavramıdır. Kısaca BIM, inşaa edilmesi planlanan yapının tüm bileşenlerinin 3 boyutlu olarak tasarlanıp, yapı elemanları ile ilişkilendirilen çeşitli bilgilerin proje süresince dijital ortamda tüm paydaşların erişimine açık hale getirilmesi anlayışıdır. Maliyet, süre ve kalite iyileştirmeleri açısında kendini ispatlamış bu yöntem İngiltere ve Amerika Birleşik Devletleri gibi gelişmiş ülkelerde belirli ölçeklerdeki devlet projelerinde zorunlu hale getirilmiştir. BIM kullanımının yaygın olduğu bu ülkelerin standartlarında BIM uygulama detayları ve olgunluk seviyeleri de tanımlanmıştır. Bu olgunluk seviyeleri sırasıyla 3D: yapının 3 boyutlu tasarımının yapılması ve gerekli imalat, malzeme bilgilerinin ilişkilendirilmesi; 4D: 3D modele süre planlama verilerinin girilmesi; 5D: 3D modele süre ve maliyet verilerinin girilmesi; 6D: yapının sürdürülebilirlik verilerinin modele girilmesi; 7D: tesis yönetim modelinin oluşturulmasıdır.
Bu tez BIM olgunluk seviyelerinden biri olan 5D'nin kapsamlı bir tanımını yapmak, 5D modelleme iş adımlarını süreç haritalama yöntemiyle belirleyerek açıklamak ve yazılım destekli test senaryoları ile yapım yönetiminde 5D modellemeye geçişin avantaj ve dezavantajlarını tespit etmek amacıyla yazılmıştır. 
Tez kapsamında ilk olarak, literatürde "BIM 5D" özelinde yapılan çalışmalar incelenerek bulgular ve mevcut gelişmeler özetlenmiştir. Geçmiş çalışmalar mesnet alınarak 5D kavramı için kapsamlı bir tanımlama yapılmıştır. Bu tanımlama ile inşaat profesyonellerine 5D'nin değişimi daha dinamik yönetebilecekleri katma değerli bir yönetim aracı olduğu belirtilmiştir. 
İkinci olarak, bir inşaat projesinde 5D modelleme yapılmak istendiğinde sırarıyla alınması gereken aksiyonlar süreç haritalama metodu ile belirlenmiştir. Uçtan uca tüm modelleme süreci için yapılması gerekenler açıklanmış, örnek 5D modelleme çalışması yapılarak 5D yazılımı ekran görüntüleri ile anlatım desteklenmiştir.  
Son olarak, inşaat sektöründeki yönetici ve mühendislerin BIM 5D farkındalığını artırmak için 5D uygulama test senaryoları tasarlanmış, bu senaryolar 5D BIM yazılımı (Vico Office Suite) ile test edilerek 5D'ye geçişin avantaj ve dezavantajları tespit edilmiştir. Tüm yapılan testler sonucunda, 5D BIM uygulamalarının inşaat projelerinde (1) hızlı ve doğru metraj alma, (2) hızlı ve doğru maliyet planlama, (3) tam otomasyon değişim yönetimi konularında avantajlar sağladığı tespit edilmiştir. Bunun yanında, 5D uygulamalarının (1) kusursuz 3D model oluşturma, (2) geometrik olmayan verilerin dinamik yapıya dahil edilememesi ve (3) tüm metraj kalemlerinin manuel adreslenmesi gibi zorlukları da beraberinde getirdiği anlaşılmaktadır. Sektör profesyonelleri için tüm bulgular konsolide edilerek BIM 5D'ye geçiş adımları açıklanmıştır.

Abstract:
For many years, there is a continuous effort to find a solution for the low efficiency rates in the construction industry and consequently for scope, time, cost creeps. Because many different disciplines have to work in a coordinated manner through the beginning of the conceptual design phase to closure processes. Besides the desired coordination and accordance environment, the nature of projects brings many change requests and it produces significant complexity in projects. It becomes an objective for academicians and experts to find new methods in order to manage prospect chaos and crisis in construction projects.
Undisputedly, the most value-added delivery of studies within this objective is BIM (Building information modeling) concept. Briefly, BIM is a management approach of designing the building in 3D by component level, attaching required information to related components, and sharing these data with all stakeholders during the project. In large scaled projects, some developed countries like USA, UK have made mandatory to use this proven method in terms of time, cost and quality efficiency. In the standards of countries that BIM is commonly in use, BIM application details and maturity levels are defined as comprehesively. These maturity levels are briefly, 3D: designing in 3D and identifying components by material types and application details; 4D: adding particularly time plan data of components to 3D model; 5D: adding particularly time and cost plan datas of components to 3D model; 6D: adding sustainability information of the structure to BIM model; 7D: adding facility management data of the building to BIM model.
This dissertation aims to make a comprehensive BIM 5D definition, clarify the 5D modeling process with using process mapping technique and determine advantages and disadvantages of BIM 5D  implementations in practice with using test scenarios supported by 5D BIM software. 
Primarily, the literature review is completed under the "BIM 5D" concept, available developments summarized. According to previous academic surveys, it is concluded that there is a considerable awareness gap for BIM and its application in construction industry. Besides, many engineers and executives believe that it is near impossible to integrate 3D design and takeoff data to time/cost plans. Included the countries which BIM is partially mandatory, many professionals think that it is not feasible to implement BIM 5D for construction projects. In most cases, BIM considered as only 3D practices and its use case is only for visiualisation of structures. Afterwards, BIM, 3D, 4D, 5D, LOD concept definitions released depending on the past studies. By this definition, its emphasized that 5D BIM is more feasible in practice when it allows the maximum level of dynamic automation in planning processes. This means that a completed 5D model can automatically make time and cost plan revisions after many types of changes in design, without any extra manual effort. This clear definition abolished the confrontation in understanding the scope of 5D.  
Secondly, all needed actions to create a 5D model are summarised as a process map. Then, all process is explained step by step supported with an end to end 5D modelling practice and related 5D software screenshots. Process begins with designing the structure in 3D design tools by component level. At the time of this study, this step totally has to be completed in 3D design tools, in other words, have to be completed out of 5D software. Completed 3D CAD model must be attached some needed information like material type, color, strength, density and so on. The finished 3D BIM model has to be registered to 5D software properly for further planning phases. If the 3D model is perfect according to clash detection, there can be a smooth transition to the takeoff process, else the 3D model must be revised. After registration of model, an LBS (Location Breakdown Structure) must be created that allow us to differentiate takeoff quantities by defined floors or regions. Then proceed to develop CBS (Cost Breakdown Structure), WBS (Work Breakdown Structure) and sub-elements of these. Next step is to map TOQ (Takeoff Quantities) with cost items and defining unit prices. With this step project budget appears. To obtain cost integrated time plans cost items must be mapped with time activities developed under WBS. And to get an expected gantt chart and 4D simulation, resource efficiencies and activity dependencies must be defined at this point. After some required plan optimizations we can get an exact dynamic 5D construction model. Making time and cost plans are usually considered as time consuming and tiring processes. To convert this process into a piece of cake, a database usability feature is added in 5D modeling tools. That means we can use past project planning datas in new projects. So to recap, 5D modeling process follows 3D and 4D modeling phases respectively.
After then, 5D implementation scenarios designed, these scenarios tested in 5D software (Vico Office Suite), pros and cons of shifting to 5D BIM summarized. Two model used for test scenarios; model 1 is a villa-type structure that has more architectural elements, model 2 is a business structure that has both structural and MEP details. Firstly, using different 3D design tools are tested by importing 3D BIM models to 5D platform. Findings are evaluated according to two metrics; issues in importing 3D model, automatic component category recognition capability. Three software are tested; Autodesk Revit, Sketch Up, Trimble Tekla. Test results show that Revit was most 5D compatible 3D design tool among tested tools. Besides the near perfectness of importing all components, Revit's element family and type classification structure are far more adaptable than others. Then LBS takeoff calculation volume creation ability is tested in many different cases. Mostly in time planning phase, we could need partially calculated takeoff quantities of civil works. To be able to calculate them all properly, it requires a well built LBS structure. Because it is founded in test results that if the LBS region boundaries cut elements nonsensically, calculation errors occur. But except this care factor, overall LBS creation capacity of 5D in floor sectioning and regioning received thumbs up. Automatic takeoff is an essential delivery in 5D modeling, so it is tested in detail. At the beginning, the calculation framework explored, Vico element categories determined that correspond to Revit's, and takeoff quantity types discovered. It is mentioned that the diversity of TOQ for basic structural components is far more than other construction elements. Furthermore, it is stated that there are two main automatic takeoff calculation error; non-defined geometry error, takeoff quantity dividing error. It is concluded that to handle these errors, there must be an effective clash detection. Because, results show that discontinuity and clashes of components are main underlying reasons of calculation errors in automatic takeoff.
With using takeoff data, project budget is created for model 2. At the backstage, a CBS created and unit prices are registered for all cost items. To automatically calculate the whole budget, all takeoff items matched with last level cost items. It is emphasized that this process needs critical attention because of tough economic consequences in case of any mistake. Besides, the project database usability for new projects tested, and successful results gathered. But there is an exception, if the takeoff item names used in CBS of the past projects do not match with the takeoff list of new project, any calculations can be made. After cost planning, time plans created for model 2. WBS and activities are created, resource efficiencies registered, then all activities mapped with cost items, automatically activity durations calculated. After all, physical and managerial dependencies are defined for every activity. By the time planning tests, it is found that Vico 5D simplified creating location-based sub-activities, and defining dependencies between sequent activities. For instance, creating and putting in order of sequent activities like formwork, reinforcement, and concrete pouring for tens of different regions in the construction field can be done automatically by just making it for only three main activities. Moreover, the flowline task dashboards, that shows location, duration and date information together, brings us to optimize teamwork and increase collaboration in the field.
As it mentioned before, the most value-adding feature of 5D in reality is offering a dynamic change management power. To understand the capability boundaries of 5D dynamic planning many tests performed. Eventually, revising an existing component or adding an element that already exists with the same name in takeoff list can be successfully recalculated for cost and time plans. The exception is the new components that added to 3D model which are not defined in time and cost plans. On the other hand, it is figured out that only geometric information can be added to 5D dynamic planning model, which is a restriction about differentiating cost or time calculations according to specific non-geometric material specifications.
In conclusion, its found out that BIM 5D methods ensure these kinds of advantages; (1) fast, accurate and detailed takeoff calculations, (2) fast and accurate project budgeting, (3) dynamic change management ability. Beside that, BIM 5D is coming with some disadvantages; (1) perfect 3D modeling necessity, (2) not being able to add non-geometric data into dynamic 5D model, (3) obligation of perfect TOI addressing. 
All findings consolidated as a simple 5D transformation guideline steps for construction industry professionals. Briefly, transformation leaders have to begin with assessing the organization and collecting expectations from 5D. Choosing the right 5D platform is a very critical point because most processes will be shaped with 5D tool's logic. The prominent criterion for 5D software is offering a dynamic planning environment. Beside, a 3D software that compatible with 5D is crucial for successful results. To have technological infrastructure is highly important but not whole. Next to technology all company processes and human resource organization must be adapted to 5D modeling mindset. Creating BIM 5D processes will align design, planning and site teams. Key factor is always human, hiring the right talents for the right positions will convey the company to success. Training employees for new processes, new software and new company culture will also boost this success. No matter how excellent your processes, employees, and technologies, there will be a continuous need for improvement. Lastly, companies have to test their all infrastructures permamently to remain successful in their 5D transformation journey.