=Paper=
{{Paper
|id=Vol-3285/paper2
|storemode=property
|title=Leveraging Digital Twins to Enhance Green Public Procurement in AECO Industry
|pdfUrl=https://ceur-ws.org/Vol-3285/paper2.pdf
|volume=Vol-3285
|authors=Silvia Meschini,Giuseppe Martino Di Giuda,Lavinia Chiara Tagliabue
|dblpUrl=https://dblp.org/rec/conf/aiia/MeschiniGT22
}}
==Leveraging Digital Twins to Enhance Green Public Procurement in AECO Industry==
https://ceur-ws.org/Vol-3285/paper2.pdf
Leveraging Digital Twins to Enhance Green Public Procurement
in AECO Industry
Silvia Meschini 1, Lavinia C. Tagliabue 2 and Giuseppe M. Di Giuda 3
1
Politecnico di Milano, Department of Architecture, Built Environment and Construction Engineering, 20133
Milan, Italy
2
Università degli Studi di Torino, Department of Computer Science, 10149 Turin, Italy
3
Università degli Studi di Torino Department of Management, 10134 Turin, Italy
Abstract
The digital transition of process management and Digital Twins (DTs) are promising to bridge
the gap towards Product Lifecycle Management (PLM) and revolutionize decision-making
processes in AECO (Architectural, Engineering, Construction and Operation) industry. Public
procurement particularly suffers of poor digitalization with ineffective processes and low
adoption of Green Public Procurement (GPP) mainly due to the lack of digital and automated
data-driven tools for tender evaluation. Leveraging DTs as virtual Prototypes (DTPs) could
help to overcome the current discrete project performances evaluation and enable a systemic
one, exploitable for bids evaluation besides performance and sustainability optimization.
The research adopts a PLM view to define a methodology aimed at developing DTPs starting
from the bidding BIM models. The main objective is to integrate several DTPs and an Artificial
Intelligence (AI) system in the aim automatizing MEAT (Most Economic Advantageous
Tender) procedure and promote GPP adoption, providing an optimal and more objective data-
driven awarding system and criteria weighting. Three crucial objectives should be
accomplished: (i) the definition of a replicable methodology to develop the DTPs, (ii) the
definition of their informative structure and (iii) the re-engineering of tender processes to bring
full digitalization and automation. This could enable more effective decisions and performance
optimization, bids objective evaluation, tendering procedure streamlining, transparency and
sustainability enhancement. The awarded DTP, as a truthful “As-built” developed accordingly
to defined information guidelines, must be exploited as the basis for valuable DTIs to manage
the whole lifecycle, optimizing DTs development costs together with operational and
maintenance costs.
Keywords 1
Digital Twin Prototype, Green Public Procurement, Tender evaluation, PLM, Waste
Management
1. Introduction
Architectural, Engineering, Construction and Operation (AECO) industry notoriously suffers of low
digitalization and productivity compared to other industry sectors. It still performs bad with limited
performances ascribable to the huge fragmentation as well as the intrinsic complexity of construction
projects with strong risk aversion discouraging new technologies uptake [1]. Such criticalities are
particularly significant in public procurement which is usually underestimated with respect to other
phases of the lifecycle as it has not an immediate impact, but it could have on the long-term, especially
on sustainability and use of environmental, material and economic resources [2]. The low adoption of
Green Public Procurement (GPP) both at European and Italian level represents an important gap mainly
AIxPA 2022: 1st Workshop on AI for Public Administration, December 2nd, 2022, Udine, IT
EMAIL: silvia.meschini@polimi.it (S. Meschini); laviniachiara.tagliabue@unito.it (L.C. Tagliabue); giuseppemartino.digiuda@unito.it
(G.M. Di Giuda)
ORCID: 0000-0001-6894-2369 (S. Meschini); 0000-0002-3059-4204 (L.C. Tagliabue); 0000-0002-2294-0402 (G.M. Di Giuda)
©️ 2022 Copyright for this paper by its authors.
Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0).
CEUR Workshop Proceedings (CEUR-WS.org)
due to the lack of simple, digital and automated data-driven tools for Most Economically Advantageous
Tender (MEAT) approach. This furtherly complicates the still highly document-based and fragmented
procedures, affecting both tender procurement duration and the awarded bid’s quality leading to waste
of time and resources.
Although BIM (Building Information Modelling) gave a boost in the last decades, neither
collaborative approaches nor digitalization are still fully accomplished. Key factors lie in struggling
information and process management due to the lack of actual interoperability and representation limits
pointed out by IFC standard [3,4]. Current BIM-based approaches, prevent to link process and data
models throughout the whole lifecycle without updates when the project state changes and to record
data change history. The solution for a breakthrough was identified in the digital transition of process
management [1] enabling tasks automation and efficiency improvements. At this aim it could be useful
a well-known approach in other engineering fields, namely PLM [5]. It supports a multidisciplinary and
systematic performance view along the whole lifecycle, enabling to manage complex processes with a
significant amount of data and strong variability. BIM was addressed as key for bridging the gap
towards PLM, but it is not enough as it was introduced mostly to improve efficiency, enable
collaboration, lower errors and omissions during the design and construction phases, with an intrinsic
difficulty in feeding models with continuously updated and complete information through the lifecycle.
Major limits lie in uncontextualized or missing process management information, in the static nature of
BIM models data without a bidirectional and simultaneous relationship with the real world.
Additionally, the synchronization of data updating is still a human task. Thus, many studies suggested
to integrate BIM in a more complex perspective [6,7] with normalized processes stored together with
data to enable data and process models linking and information contextualization.
A recent growing trend is promising to bridge the gap towards PLM and more sustainable choices
in AECO industry, namely Digital Twins (DTs) [8]. Their interlinked and dynamic nature could be the
solution for the management of complex systems such as those concerning construction projects,
enabling an actual revolution in Information Management (IM) and decision-making processes. This
especially with the aim of enhancing public procurement productivity and promoting GPP [9] adoption
as required by EU directives and Italian Legislative Decree (L.D.) 50/2016.
Although a unique definition of DT in AECO industry has not yet been formulated, its first
formalization was provided by Grieves in the field of PLM [10]. In this perspective, the DTs could be
developed starting from the early design phase as DTPs, with the dual objective of optimizing project
performance and structure the basis for the future DT Instances (DTIs) exploitable in the lifecycle. DTs
market is expected to grow exponentially in the coming years with major part of buildings foreseen to
have a virtual twin providing added value thanks to the easily information and process management
through the lifecycle [11]. Thus, it is advisable to implement the DT starting from the early design
phase, optimizing the use of resources, developing time and costs, in addition to operational and
maintenance costs. This could help to over-come the current discrete project performances evaluation
in favor of a systemic and full digitalized one, useful for bids assessment, performance, and
sustainability optimization.
With the aim of encouraging GPP adoption, the research proposes an innovative and automated
MEAT approach based on the integration of DTPs, normalized processes and an AI system through an
open-source distributed platform based on Web of Linked Data principles. Leveraging DTPs during the
tendering phase by aggregating them in a DTPs System exploited in a virtual ecosystem enables to
evaluate different design proposals [10], optimizing decision-making and identifying the optimal
solution. The key concept is that the DTPs must not be disposable but reusable as the basis for future
DT Instances (DTIs) which will gather also dynamic data from field to manage the whole lifecycle. At
this aim the DTPs should be developed starting from the BIM biddings models submitted accordingly
to a defined IFC schema, exploiting Semantic Web and Linked Data principles [12,13] with easily
accessible information stored in the open-source collaborative platform, also facilitating the DTPs
enrichment throughout the lifecycle. The main goal is to provide an optimal and more objective data-
driven awarding and criteria weighting system, in addition to a full digitalized and automated evaluation
procedure, providing tendering procedure streamlining, transparency and sustainability enhancement.
The paper presents a methodology aimed at developing vertical DTPs (VDTPs) and then
horizontally integrating them in a DTP system for the automated criteria evaluation in MEAT
procurements. At this aim, three crucial objectives should be accomplished, that is: (i) the development
of a replicable methodology to develop the DTPs, (ii) the definition of their informative structure,
related Information Requirements and how data should be gathered and (iii) the normalization and re-
engineering of tender processes through BPMN 2.0 (Business Process Modelling Notation) [14] in a
machine-readable way to bring full digitalization and automation.
Due to the numerous and complex domains integrated in a construction project, a scalable approach
is adopted. With the aim of overcoming the lack of automated and user-friendly tools enabling
sustainability criteria evaluation, the developed methodology will be tested starting from the evaluation
of the mandatory yet not fully applied CAM (Minimum Environmental Criteria) [15]. A Sustainability
DTP will be developed and firstly tested for the automated evaluation of waste quantities in two real
Italian Design-Bid procedures [16]. Waste generation could be considered starting from the early
designer phase and this is key to optimise quantities and reduce the environmental impact of the project.
Assessed and validated in comparison with previous developed approaches, the methodology then will
be extended to other CAM criteria and could be further extended providing the whole tender evaluation.
2. Background and motivation
2.1. A process-based open-source collaborative web platform
The research is conducted under the umbrella of an Italian Research of National Interest Project
(PRIN) which promotes the digital transition of project management aiming at overcoming the afore
illustrated limitations posed by current BIM-based collaborative approaches [17]. The goal is to
integrate data and process models throughout the whole lifecycle in a collaborative process-based
framework by jointly stored them through typed links with a customized semantic. Web of Linked Data
technologies will be exploited [18]. In particular, the framework is based on the following technologies:
• Semantic Web to translate BIM models in graph format (i.e. RDF) through tailored
ontologies;
• Linked Data to enrich BIM models with missing data by interlinking them from different
domains through customized typed links;
• BPMN 2.0 to define and formalize data generating processes in a machine-readable way,
enabling external actions (i.e. from humans or micro services) to be called [19].
• Blockchain at the top level aimed at the decentralized notarization of transactions and
documents liability tracking [20].
Accordingly, the major outcome of the PRIN project consists in an open-source, distributed,
collaborative platform to enhance cooperation in an easy-to-use digital environment. The involved
research units should develop several Proof-of-Concept (PoC) use cases to demonstrate the easy
collaboration and information exchange. The present research deals with the PoC use case for the design
phase with the goal to exhibit how checking procedures could be developed and automated throughout
the Web of Linked Data platform and how links between design data, processes and system
performances can be formalized, depending on the evaluated criterion. A key concept to maintain
information requirements consistency through the design phase and the whole lifecycle, avoiding
shifting away from the original intent, especially in competitive biddings. Linked Data and Semantic
Web combined with IFC through the Web of Linked Data platform provide a highly scalable and
customizable approach for the DTs definition. IFC models could be translated in graph format with
missing parameters to generate DTPs linked through tailored typed links. Such DTPs can be initially
fed by bidders input and then incrementally enriched as the lifecycle of the building progresses.
2.2. Digital Twins: the bridge towards PLM
NASA provided the first formal definition of a DT, but the general concept was firstly provided by
[10] in PLM by defining the fundamental elements of a twin model: the real part, the digital part and
the information links between them [21]. Grieves identified three types of DTs with a growing level of
maturity and they are conceived as dynamic and evolving models throughout the lifecycle. Firstly, the
DT emerges virtually with the DTP and then takes physical form during the production phase and the
operational phase as DTI, until the disposal. It should be noticed that at the early stage the physical
system does not exist yet and the DTP takes place in a virtual space identifiable with the digital space
of information models. Before the advent of computer design, the system had to be costly implemented
in a physical prototype. Now, very complex systems and shapes can be easily modelled with no need
of a physical mock-up and the DTP could be exploited to predict future behaviour and performance of
the product (i.e. building) in order to check when it represents the optimal solution and meets the
proposed requirements [11]. DTs are gaining attention in AECO industry due to the increasing
complexity of construction projects and the widespread integration of digital tools which provided a
constant increase of data to be managed throughout the building lifecycle. So far, there is no commonly
agreed definition of a DT in AECO industry, but almost all the attempts include the three key features
aforementioned [20, 21]. Many studies agree that there might never be a universal definition of DT;
rather its meaning depends on the developing purpose. Indeed, the great value provided by DTs lies in
the ability to obtain the right information at the right moment. Thus, it should be tailormade based on
its scope of replicating some behaviour of the physical asset avoiding replicating every part of the
building. On the contrary, its bidirectional link with the virtual world is essential, enabling simultaneous
data updating as soon as a change occurs. Some studies already made a parallelism with the DT types
defined by Grieves, in particular [22] borrowed the DTP definition to the Building DTP: "A Building
Digital Twin describing the AECOO asset during its design and construction. It contains the
informational sets necessary to describe and produce a physical version that duplicates or twins the
virtual version." Accordingly, during the design and tendering phase, a Building DTP should be
exploited in a virtual world evaluating different design proposals to identify the optimal one (i.e. the
most advantageous bid). This could be disruptive as until now construction projects were a siloed set
of project performances, evaluated through document-based approaches which prevented to estimate
the impact that a change in input could have on the single and overall project performance. No prototype
of the building with a holistic view of its performances was available and projects’ comparison
concerned just single parameters disjointed from their impact on installation and maintenance costs or
resources consumption. A well-structured DTP can provide a complete and valuable prototype,
allowing to evaluate the designed performances and choose the most sustainable solution also with
respect to the expected savings. Nevertheless, although [10, 22] agree that the DTP “…has to contain
all the informational sets necessary to the future actual physical twin (DTI)..”, the DTP structure and
information requirements related to the several performances to be evaluated is still undefined. As [23]
points out, few research investigated the DT across the whole lifecycle, highlighting several gaps
especially concerning the early design and disposal phases. This suggests that the actual benefit might
have been missed yet and that the DT information requirements across the lifecycle should be
investigated to provide valuable applications in a PLM perspective, in addition to useful information
protocols for DTP development. An IM approach is strongly recommended as suggested by the IM
Framework in the pioneering case of the National DT Britain [24].
2.3. Need for a green and digital transition of public procurement
The 14% of the European Gross Domestic Product is represented by Public Procurement and is
regulated by EU directives with the aim to maximize value in the public sector and ensure compliance
with three key principles: equal treatment, non-discrimination and transparency [27]. EU commission
measured the performance of single markets in State Members to understand their public procurement
efficiency [27] pointing out a bad performance for Italy with just two satisfactory indicators among 12
and the "Decision Speed" among the six not satisfied. [28] highlights an average starting time of a
public procurement of 4 years and 5 months with the tendering phase averagely lasting between 5 and
20 months. The main cause of long “processing times” (i.e. the time between the end of one phase and
the start of the subsequent one) lies in bureaucratic delays [25, 27]. Concurrently, both at international
and European level, GPP is promoted to integrate requirements and criteria in order to achieve value
for money in the whole lifecycle of a project and reach more sustainable practices. The 2014/24/EU
Directive emphasizes the key role of Public Clients in realizing a smart, inclusive, and sustainable
growth. Italy was pioneering with the innovative L.D. 50/2016 which introduced GPP as mandatory in
public tenders through the MEAT approach. The most convenient bid must be identified by crossing
price and quality, based on the lifecycle performance of a project. Nevertheless, GPP is still poorly
adopted mostly due to the lack of staff training and competences, generating issues in drafting
sustainability criteria for tender documents. A worsen factor is the lack of digital and automated tools,
preventing Public Clients to control project impacts in terms of both performance and sustainability.
Furthermore, although the requirements of L.D. 50/2016 for the application BIM, project deliveries are
still document-based struggling the whole bids documentation checking.
Therefore, digital, automated, and data-driven methods would be fundamental to enable easily
project performance control and visualization promptly displaying the impact that some design choices
might produce both at single and global performance level. It is key to provide administrators, judging
commission and all the involved parties with actual awareness of their choices and sustainability impact.
At this aim, a system of DTPs receiving offers in real-time through a web-based platform and enabling
their timely evaluation and visualization at once would be essential albeit very complex:
3. Methodology theoretical overview and path description
Firstly, the methodology theoretical overview is provided to clarify research boundaries and
objectives, then the replicable methodology path to leverage DTPs and AI through the Web of Linked
Data platform and automatize MEAT in Design-Bid procurements is illustrated.
The principal axiom of the present research is that the developed prototypes must not be of the
“disposable” type and intended just for the tender phase, rather it must be scalable and reusable to enable
aware and optimized decisions concerning sustainability (e.g. costs, use of resources, compliance with
environmental protocols, etc.) during the whole lifecycle. Thus, it must be framed as Grieves did in
PLM and as [22] did in AECO industry. The research intends to provide a step forward with a DTP
development methodology and detailed informative structure exploitable both as a mean for tender
evaluation and as the basis for future DTIs. The DTPs born virtually in the tender phase as a tool
exploitable in Design-Bid procurement to automatically evaluate the technical offers uploaded through
a web-based platform. Therefore, their inputs are represented by the static project parameters
extrapolated by a tailored IFC bidding model exploitable to develop all the DTPs needed in the bids
evaluation and awarding. Another axiom concerns the fact that the proposed methodology is tailored
with respect to Design-Bid procurements with a definitive project in which the Appointed Party realizes
the final design and executes works.
It represents a valuable framework for the application of IM approaches [28, 16], especially with the
aim of developing DTPs since the geometry of the project is defined and the bids are based just on
performance improvement proposals. Moreover, defining a DTP exploitable as the basis for the DTI
for the lifecycle management of a project with low import or less complex awarding criteria and a
simple O&M phase, would be unproductive and antieconomic due to the huge effort required. For each
criterion involved in the evaluation, VDTP will be developed, enabling the analysis of the single side
performance. Then all the VDTPs related to an offer will be horizontally integrated in a Digital Twin
Prototype system (Figure 1) useful to evaluate the single bid global performance and the impact on the
overall. As it still lacks the definition of an informative structure for the DTP with related information
requirements, the focus is not just the development of the DTPs, and the attention is centered on the set
of processes and information concerning the creation and management of tailored DTPs.
It is not feasible to develop the whole DTP system enabling to simulate all the project performances
at once, thus a bottom-up approach is adopted in order to define a replicable methodology useful to
cover all the criteria/project performances. The methodology will be tested starting from CAM criteria
evaluation and then extended. It starts form waste management criteria as part of a wider Sustainability
DTP which will comprehend all CAM criteria. The research aims to exploit a previous work which
dealt with Construction and Demolition Waste (CDW) minimization and selective demolition criteria
and defined a replicable IM Modelling (IMM) approach to consider CAM criteria from the design to
the call for tender phase [16]. The long-term objective is to extend the previous work in a more holistic
approach by adding further CAM criteria evaluation such as building envelop performance in addition
to lifecycle and disposal costs. In the short-term the previous case studies are exploited to test the
validity of the methodology and the potentials of customized DTPs in enabling sustainability criteria
automated evaluation with a holistic digitalized approach, improving GPP. Following the description
of the main steps and tasks of the proposed methodology.
Figure 1: Digital Twin Prototypes horizontal integration in the DTPs System.
3.1. Tender processes normalization.
The first step concerns the formalization of all the processes and sub processes related to the offers
evaluation, namely: (i) the global tender procedure, (ii) bid evaluation method, and (iii) evaluation of
single performances considered. As stated before, BPMN 2.0 will be exploited, providing an intuitive
graphical notation yet capable of representing complex semantics and machine-readable processes (i.e.
xml format) able to call external interventions from humans or micro services. This normalization
enables to identify both the information needed at a specific step of the process and by the related actor,
that is the information requirements for each VDTP needed, and automatable tasks. Consequently, it is
possible to check which input could be directly filled in the IFC bidding schema and which one should
be linked through LD. The BPMN formalization allows also to define the needed outputs for single
criteria and sub-criteria evaluation, in addition to the queries and rules to extrapolate needed information
for VDTPs from the Web of Linked Data platform. Finally, the availability of machine-readable,
normalized processes enables their optimization and automation through AI systems.
3.2. Vertical Digital Twins Prototypes and KPIs definition.
In this second step, VDTPs will be developed from the IFC models submitted by the participants
and stored in graph format through the Web of Linked Data platform. Thanks to the previous BPMN
formalization, the information requirements for each VDTP needed in the global evaluation are known
and the models could be enriched accordingly to generate them. A key step is the definition of the
queries to generate needed simulation models from the knowledge database and the KPIs (Key
Performance Indicators) which could be monitored to promptly correct any deviations from expected
targets. Ideally, for each bid should be developed as many VDTPs as the number of tender evaluation
criteria, starting from each bidding IFC model developed basing on the given scheme and stored in
graph format through the Web of Linked Data platform. The main outcome consists in a series of
isolated VDTPs enabling single performance evaluation. It may seem onerous, but once needed VDTPs,
related information requirements and extrapolation query are defined the process can be reiterated for
each bid and machine learning could be exploited to automate this task.
3.3. Digital Twin Prototypes System implementation
Once the VDTPs are defined, they will be horizontally integrated to set-up the holistic evaluation of
each bid’s project performance (Figure 1). This step will involve the formalization of the
interconnections to set-up the DTPs system, enabling the definition of the links between the VDTP. A
major outcome will be the simultaneous visualization of both global and single bids scores by means
of tailored dashboards implemented through the Web of Linked Data platform. Thus, the user can be
aware of the impact that a change in input has on the project performances, both at global and local
level, in addition to costs and sustainability. A major outcome at this step will be the definition of the
queries which enables to implement the DTPs system needed for the global bid evaluation (i.e. one
DTPs system for each bid or tender project), based on defined information requirements.
3.4. AI system integration and global tender evaluation
A key step will concern the implementation of the most suitable AI system to provide the automation
of MEAT approach, that basically is a multicriteria analysis [29, 30]. Furthermore, AI will enable the
sensitivity analysis of the information requirements both of the single VDTP and of the overall system
(i.e. DTPs system and tender evaluation). This enables deeply understand how a change in input impact
on the single VDTP and on the overall, revealing hidden and direct links between various project’s
domains and enabling their formalization. As real cases are simulated, the AI system can be trained
providing a growing knowledge of such links between the involved parameters in the tender evaluation.
Then it will be possible to define and optimize a multicriteria scores aggregation system also
considering the impact that a parameter change has both on the single performance and on the global
one, in addition to that on sustainability and costs in a PLM perspective. In fact, increasing a single
parameter performance doesn’t ensure significant positive repercussions also on costs or global
performance. Rather, it might lead to greatly increased installation and maintenance costs compared to
slight savings. Exploiting AI and it could be provided a more objective, effective, and aware bids
evaluation system.
3.5. Proof-of-Concept: Sustainability DTP for automated CAM criteria
evaluation in Design-Bid procedures
The final step concerns the PoC development aiming at applying the proposed methodology to real
case studies and analyse the benefits and criticalities of the innovative tender approach. As already
stated in previous sections, the research aims to further promote the adoption of GPP in Design-Bid
procedures and take a step forward respect a previous study [16] providing a holistic, automated tender
evaluation and awarding. The methodological path and tools described in previous section are here
contextualized and implemented through two Design-Bid Italian procurements for new school
buildings. Aiming at CAM checking, the application of the proposed methodology starts from the
automated evaluation of the waste quantities and disposal costs related to the “Final dismission” CAM
criteria which will be part of a wider Sustainability DTP that in the future will consider other categories
providing a multidisciplinary approach. Leveraging it from the tender phase will enable to optimise
quantities and reduce the project environmental impact with a better resources allocation and
optimisation by choosing materials with low waste quantities and low disposal costs. A systemic and
simultaneous bids performance evaluation will be gained providing a multidisciplinary approach.
Furthermore, information requirements and protocols to define which quantities each bidding model
must contain to enable the automated evaluation will defined along with KPIs useful to check project’s
environmental impact and the proposed approach validity, compared to other approaches.
3.5.1. CAM criteria in MEAT tender and case studies
The first case study is the Design-Bid procurement for the final design and construction of the new
primary school in Melzo (MI), involving a total budget of €5 M for the construction of a single building
hosting 500 students in 3’523 square meters. The project was developed in 2015 without including
CAM application, but only the control of hazardous waste as required by the regulations of the time.
BIM was applied in the design phase as well as in the drafting and management of the tender to
minimize environmental impact [29]. Environmental criteria amounted at more than 40 points and the
waste management criteria directly and indirectly involved 15 out of 100 points. The second case study
concerns the Design-Bid procurement for the final design and construction of the Inveruno school
complex (MI). The call for proposal ended in 2020, it had a higher level of complexity with a total
budget of €15 M for three building complex hosting 675 students in 7’477 square meters, in addition to
the 240 hosts of the Auditorium. The project area was as a brownfield according to Lombardy Region
regulation and the project involved a significant demolition phase. Environmental and CWD
management criteria provided the assignment of 27 out of 100 points.
Design-Bid procurements imply the use of MEAT evaluation introduced by D. Lgs. 50/2016 to
consider the quality/price ratio calculated throughout the building lifecycle. Accordingly, bids
evaluation is based on quantitative and qualitative criteria, linkable to qualitative or quantitative classes
so that objective alphanumerical criteria and their quality assessment is based on defined rankings. The
innovative approach will be applied to evaluate bids according to their waste management and
environmental impact (Table 1).
Table 1
Selected criteria and sub-criteria involved in the evaluation of bids waste management
Categories Criteria Sub-criteria Evaluation sub-criteria
A.2 Building A.2.1 - Distance to the production site of the
Passive
materials materials
A elements
requirements A.2.3 - Degree of materials maintenance
requirements
A.3.1 - Contractor certification according to
A.3 Environmental UNI EN ISO 14001
requirements A.3.2 - Producers certification according to
UNI EN ISO 14001
Construction C.2 Constructive C.2.2 - Construction site layout
C
site solutions and site
management C.2.3 - Waste management
3.5.2. Automated waste management criteria evaluation workflow
Figure 2 shows the overall waste quantity evaluation process. Bidders will upload their offers
through the Web of Linked Data platform as IFC models developed accordingly to the information
requirements defined.
Figure 2: Overview of the waste management criteria evaluation process through the Web of Linked
Data platform.
Then they will be translated and stored in RDF together with process models and other needed data.
When the platform receives the request to check and evaluate waste management criteria, the related
BPMN process is recalled, enabling a query to extrapolate the Sustainability DTP of each bids which
contains waste quantities classified accordingly to European Waste Codes (EWC) and disposal costs.
In particular, each bid model must contain waste quantities divided and weighted according to four
percentage for: reusing, recycling, landfilling of hazardous and non-hazardous waste.
Then, the bids awarding process based on MEAT and multicriteria analysis is recalled and requires
the interaction with the selected AI algorithm to evaluate waste quantities, their disposal costs and
environmental impact, in addition to assign a score depending on the given weight in tender documents.
AI will be exploited also to optimize the criteria weighting, considering the impact that a change input
has on the global and single performances, depending on which criteria should be stressed more. So, it
will be possible to visualize bids awarding and defined KPIs to compare this method with previous
ones. The step forward concerns the use of open standards, required by the most recent regulations, the
automated and data-driven method in addition to a better-defined IM approach.
The methodology is still at theoretical level and the results are discussed as expected outcomes to
be whether confirmed or not through the PoC. The global worth lies in the full digitalization, shortening
and transparency of the tendering phase, while the disruptive worth concerns the leveraging of an
innovative approach exploiting DTPs and AI through an open-source, distributed digital framework and
automatize sustainability criteria evaluation in Design-Bid procurement. Adopting a PLM perspective
and defining valuable building DTPs suitable to develop actual DTIs to constantly monitor the
identified KPIs throughout the building lifecycle, an actual GPP could be provided by pursuing the
highest possible degree of sustainability in terms of performance, use of resources and lifecycle costs.
A revolution in current public procurement procedures which prevent to exploit simulation models to
evaluate bids. Table 2 shows the comparison between the main features of current evaluation approach
and the proposed one. Currently, the experts commission is central and judging bids based on own
professional experiences, with poor objectivity. The proposed method, based on the evidence provided
by performance simulation through the DTPs system holistic view, foresees commissioners with a
marginal, notarial role with an improvement in objectiveness and costs reduction, as well as the easier
identification of the most sustainable solution. A powerful digital simulation tool (i.e. the DTPs system)
will be exploited to handle bids evaluation. Thanks to the formalization and digitalization of the
processes involved in MEAT procedure, greater objectivity and transparency will be provided.
Furthermore, the key role of the Public Client in the green and digital transition becomes evident as the
Appointing Party becomes an active part of the evaluation process, defining clear information
requirements and avoiding receiving random bidding documents. Moreover, performances will be
evaluated with a homogeneous, multidisciplinary and systemic method, as soon as the bidders upload
their offers on the web-based platform. Offers can be simultaneously evaluated with a drastic reduction
of tender assignment time, switching from an average of 5 to 20 months to few days (Table 2).
Table 2
Comparison between current tender approach and the proposed DTPs system (DTPS)
Current approach DTPS perspective
Web of Linked Data platform,
Evaluator Judging commission
commission partial actions
Excel sheets Digital microservices
Tools
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Awarding criteria Objective, automated through an AI
Subjective, manually, based on
weighting system, based on single and global
commissioner’s experience
impacts
Performance
Siloed set of performances Systematic and simultaneous
evaluation
Tender duration 5-20 months Strongly reduced, few days
Finally, the developed DTPs system and the collaboration between parties can enable to exploit the
awarded project to furtherly maximize the potential sustainability and minimize both maintenance and
construction costs before developing the DTIs system exploitable during the rest of lifecycle. The
awarded DTPs system can be exploited by the Appointing Party to easily visualize the impact that
design choices have on defined KPIs and project performances, enabling more effective and conscious
sustainable choices. It provides a holistic view for bids project evaluation, enabling to quickly and
automatically check whether the tender information requirements were met or not, avoiding shifting
away from the original intent.
The sensitive analysis conducted by an AI system enables the formalization of the existent direct
and hidden links between project performances, supporting more aware and effective design choices
starting from the design phase. It will enable to promptly understand how the modification of an input
might affect both the DTPs involved and the global performance. As the DTPs are simulated, it could
be defined a hierarchy among the award criteria and KPIs based on their impact on project performance,
costs and sustainability, optimizing MEAT evaluation method and information requirements for
valuable DTPs. This lead to define trustworthy standards, information, and process management
protocols for the tendering phase.
4. Conclusion
The paper tackled the overcoming of current BIM-based approaches towards a PLM perspective
borrowing the DTP as conceptualized by Grieves and leveraging it to fully digitalize and shorten
Design-Bid tender procedures with MEAT. A replicable methodology is proposed to develop DTs
starting by the tender phase, providing a holistic approach for project performance optimization through
a DTPs system which can be exploited to evaluate and award the optimal bid with respect to the client’s
requests and regulations, and to the overall sustainability.
The boundaries of the research were defined, among them the principal ones are the framing in
Design-Bid procurements with MEAT and the developed DTP which must be a "reusable" prototype
throughout the whole building lifecycle to provide the DTIs for other phases. The replicable
methodology is developed to be used through a Web of Linked Data platform in the aim to develop
DTPs with a highly scalable and enrichable information structure. Moreover, it enables to extrapolate
and link together several correlated DTPs, resulting in a DTPs system which enables the systemic
evaluation of performances. There are many challenges along with the advantages proposed. Among
them the identification of information requirements and ontologies for each VDTP needed, due to the
numerous and complex domains integrated in a construction project. A replicable and scalable approach
is adopted, and the proposed methodology will be tested through a PoC on two real Design-Bid Italian
procurements previously exploited in another work to promote waste reduction and resources
valorisation. The aim is to extend previous work in a more holistic, automated approach which includes
further CAM criteria evaluation. The CAM criteria to be evaluated were identified and expected
outcomes and results are discussed, illustrating how a DTPs system could enable sustainability criteria
automated evaluation and increasing both GPP adoption and digitalization enhancement in tendering
processes. Another challenge concerns the disruptive transition from to the proposed approach which
ensures full digitalization and transparency among stakeholders. This is due both to the closeness of the
sector and current Italian regulations. Nonetheless, the evaluation on real case studies is meant to
demonstrate the system validity and propose a twisting to the current evaluation method, providing a
more objective, shortened, sustainable and transparent one. It is also identified the crucial issue to
integrate the best AI system to conduct sensitivity analysis and identify direct and hidden links between
the inputs. Thus, the significant ones with respect to award criteria and defined KPIs could be
formalized, enabling to understand almost in real-time how a change in design choices influence the
overall and the single performance.
5. Acknowledgements
Work supported by (MIUR, 2017), PRIN project. The authors want to thank BIMgroup lab from
Politecnico di Milano for the collaboration to the research project.
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