Hybrid Project Management: A Literature Review

: After a wave of traditional and agile project management, there has been a visible period of blending these archetypal approaches in their combination, represented by hybrid project management. Although it has received considerable attention in the literature and practice, this phenomenon needs more conceptualization, clarity for the whole approach, explicit anchoring, and clear boundaries. This paper aims to define the meaning of hybrid project management more firmly through a narrative review that analyses the delineation of existing research and critical synthesis. The output also clarifies the blurred boundary between the edges of hybrid and traditional or agile project management. The benefit of this anchoring is the cultivation of the project management scene and the attempt to limit vagueness and misuse of the term.


Introduction
Organizations address increasingly complex initiatives, problems, and requirements in today's rapidly changing environment, putting pressure on them to adapt continuously to dynamic conditions (Horney & O'Shea, 2015).These conditions, sometimes referred to as the VUCA world, an abbreviation for volatility, uncertainty, complexity, and ambiguity (Bennett & Lemoine, 2014), create new project management (PM) challenges (Papadakis & Tsironis, 2018).
After a period in which traditional project management (TPM) dominated the project management field and after the subsequent 20 years of development of antitheses represented by agile project management (APM) and mutual delineation (Gemino et al., 2021), attempts to combine these two archetypal extremes were made.The effort to find optimized combinations based on multiple, typically conflicting methodologies has led to the emergence of various methods or frameworks collectively referred to as Hybrid Project Management (HPM).
Based on positive experience and research results, we observe a gradual development of hybrid methods that optimize project outputs by combining multiple methodologies at different levels.Despite this success, across the hybrid project management phenomenon, we face the problem of unclear boundaries of what is still HPM and what is not.For example, Serrador and Pinto (2015) found the prevalence of "hybrid" Agile methods.They suggested focusing on companies, which formally adopted a hybridized version of Agile, and their doi: 10.36689/uhk/hed/2023-01-034 research has found that the hybrid approach applies to most projects.For a measure, they asked respondents to indicate the amount of effort spent planning during the planning and execution phases and constructed the Planning effort index and Agile planning index.The indices differed in the numerator -total effort expended during the planning phase was used for the Planning effort index, and total effort spent on planning after the planning phase was used for the Agile planning index.Gemino et al. (2021) used a 5-point Likert-style format which asked respondents to identify the percentage of agile practices used in their project.Projects in the highest category with agile practices, between 80% and 100%, were categorized as agile, and projects in the lowest category with agile practices, between 0% and 19%, were considered traditional.The remainder of the scale results in categorizing the projects as a hybrid.The authors justified the 20% cut-off as reasonable because it constitutes reasonable use of the other approach since "the definition of hybrid is combining practices from agile and traditional approaches" (Gemino et al., 2021, p. 165).Different studies define the approach differently, commonly referring to a specific case of a combination of agile and traditional approaches, but other varieties exist.There is only fragmented knowledge about the hybrid approach (Reiff & Schlegel, 2022).What constitutes HPM is unclear, and the determination of what combination of agile and traditional approaches is enough needs to be clarified.Is a traditionally planned project with a work package organized with Scrum hybrid?Or an agile IT project with set milestones and 10% of requirements planned upfront?Academia and practice have made efforts to determine when it is appropriate to use HPM, while at the same time, it is not obvious what is and what is not HPM.
Another motivation for refining the definition of HPM is the desire to cultivate the field of project management so that the term is not misused similarly to Agile.In the same manner, as the naming of Agile has been used to refer to poorly or loosely managed change, HPM can be used to name projects that are not consistently following one of the methodologies, if not anchored.
By the narrative review method, this paper looks at the definitions and delineation of HPM in previous research on the phenomenon.Based on these inputs, we do not attempt to provide the reader with a raw average of these definitions but to further refine it through critical analysis and outline the phenomenon's boundaries.This method aims to answer the question of what hybrid project management is and whether it fits the current VUCA world.

Methodology
This study focuses on type 3 research, which reconciles the need for theoretical development and engagement with practice and encompasses the meso level dealing with project-level explorations according to Geraldi and Söderlund (2018) framework.We conducted a narrative literature review to answer the research questions utilizing objective, comprehensive and critical analysis of current knowledge.For practitioners, it helps create a reliable knowledge base that can be used for evidence-based decisionmaking, and for academics, the review process increases methodological rigor (Tranfield et al., 2003).
To ensure a systematic, transparent, and rigorous process as possible, we followed the comprehensive guidance of the PRISMA 2020 statement (Page et al., 2021).We searched two of the largest and most popular (Paul et al., 2021) bibliographic databases, Scopus and Web of Science.
Search strings are listed in Table 1.As we planned to use machine learning tools to prioritize the screening, we kept the search string very simple to ensure that relevant studies were not omitted due to the over-specificity of the search.For screening records, we used ASReview, which uses active learning to train a machine learning model that predicts relevance from texts using a limited number of labeled examples (van de Schoot et al., 2021).The resulting number of search records was in the thousands, and it would be too time-consuming to screen them manually.However, using the tool eliminated this disadvantage, as we assumed based on previous experience.ASReview not only offers a much quicker way to select relevant literature than screening by hand, but it also automatically logs every screening decision, which benefits the transparency and reproducibility of the reviewing process (van Ruitenburg & Ruiter, 2022).
Records that passed screening were then sought for retrieval of the full text.Only studies in English were included, so there was no need to translate abstracts or full texts of articles.
Table 2 lists the inclusion and exclusion criteria used to assess eligibility for inclusion in the review.For eligible articles, relevant information related to descriptive data (type, title, authors, year, DOI, etc.) and information relevant to the research question were extracted in a structured fashion using an extraction table in Microsoft Excel.

Inclusion criteria
Exclusion criteria HPM is an objective of the article.
The article text is not in English.The definition of HPM is included.
There is no full text of the article available.The article does not address the research question.
The article is duplicate report of the same study.
The article is a teaching case only.
Full texts were read from start to finish.They were inductively coded using initial codes (Gaur & Kumar, 2018;Xiao & Watson, 2019) in MAXQDA2022.We utilized theoretical thematic analysis (Braun & Clarke, 2006) to analyze the coding outcome.An online platform, Miro, was used for effective collaboration among the authors and as support for visualization.

Results
We found 6,129 records in database searching (3,885 in Scopus and 2,244 in Web of Science).Deduplication was performed, and we screened 4,623 abstracts of records using ASReview, a machine learning-aided tool applying active learning (van de Schoot et al., 2021).After the screening, we retrieved 91 full-text papers, assessed them for eligibility, and included 46 papers.In addition, we searched the references of the originally included studies.
Additional 36 full-text documents were retrieved and assessed for eligibility, and 16 fulfilled where they lie, it is necessary to answer what we are talking about.Is hybrid project management a method, a methodology, a framework, an approach, or a combination of practices?Even this initial question varies from research to research, and these terms are treated loosely (see Table 3).More than half of the included articles use the term approach, the term model is also often used, and the term method or methodology is also repeated.
Other designations are not typical and are relatively rare.As part of the analysis, we also analyzed how the components that the hybrid creates are described (see Table 4) and whether the HPM description also includes the reason for creating the HPM (see Table 5).The vast majority of articles define HPM as a combination of agile and other components.Four articles generally describe that a hybrid is created by combining different approaches, and two studies mention a combination of predictive and adaptive methodologies.As for the component combined with agile, the label traditional alternatively conventional predominates.Individual studies often use waterfall, plan-driven, stage-gate, and V-model, especially in fields where these terms merge with traditional project management approaches.
The reasons for the emergence of HPM are the most variable in the literature.The most common goal is to obtain the advantages of a combination of approaches, eliminate their disadvantages, or both.Nine studies cite adapting the methodology to their needs as a reason.Seven articles highlight the introduction of agile elements into traditional PM.Other reports also mention project success, project performance, balancing flexibility with a structured approach, or, more generally, obtaining a more effective model for project management available.
Table 5.What is the reason for creating HPM according to the literature to gain benefits of both 16 to customize to the needs 9 to reconcile the traditional approaches with agility 7 project success 6 combining the strengths while suppressing weaknesses 5 project performance 5 to balance structure and flexibility 5 to develop an effective model 4 to negate the disadvantages 3 to comply with constraints 1

Anchoring HPM
The emergence of HPM and the appropriateness of its approach to PM is supported on a theoretical level by the project contingency theory (Howell et al., 2010) and the associated body of work, which states that not all projects are the same, and therefore they should not all be structured and managed the same way.
Project management has many descriptions, but one of the respected and cited definitions is Packendorff's formulation stating that PM can be described as "a set of models and techniques for the planning and control of complex undertakings" (Packendorff, 1995).
It is a concept including multiple theories applicable to different projects considering that publications often differ in their prescriptive or descriptive attitude.Here hybrid project management builds primarily on its descriptive approach, which is based on the analysis of use cases in the company where a specific methodology was formed.This is the approach that Packendorff recommends for future project management research and is in direct opposition to the academic attempt to build a specific prescriptive framework.
Hierarchically, we equate HPM with APM and TPM.Neither is a specific methodology or framework that contains a specific prescription for how to lead a project or temporary organization under given assumptions.However, both mentioned above represent several of these methodologies that share the same principles or values.For example, ISO 21500 and the first versions of the PRINCE2 and PMBOK standards are representatives of TPM (although they can no longer be clearly defined as such because recent versions of international PM standards have already incorporated agile into possible PM approaches: e.g.PRINCE2 Agile or PMBOK 7th Edition).Similarly, APM includes, for example, Scrum, Adaptive Software Development, Extreme Programming, and others.At the same time, TPM and APM are approaches that are defined by a series of characteristics, principles, and values that defines the approach.
We look at the definition of HPM at the meso level, which represents the classic project management body of knowledge, including project-level explorations, collaboration, cooperation, coordination problems in projects, time management, and communication management (Geraldi & Söderlund, 2018).Through this lens, the hybrid concept fulfillment is represented by the combination of the sub-elements of a project, not by a combination and dependencies of several projects with different methodologies which would form a program.
The most significant intersection between the analyzed definitions of hybrid project management is that it combines several diverse methodologies.Furthermore, publications agree that one of the characteristics is the objective of selecting from the mentioned methodologies their advantages, avoiding their disadvantages with the vision of providing more successful projects.Beyond this typical minimum, publications often differ in what is combined from these methodologies, whether we combine practices, principles, or methods.
In order to get rid of the current vagueness of the definition of hybrid project management, we need to pay attention to its boundaries.As mentioned above, HPM is not a specific methodology but a PM approach mixing traditional and agile methods, not least because it does not tell us the specific elements of other methods that must be included.The definitions of hybrid project management described above do not show the sharp boundaries of HPM itself and, therefore, implicitly indicate the boundaries where traditional and agile methodologies end.
In traditional methodologies, tailoring has long been the method of choice.That is the systematic departure from a particular traditional methodology in favor of other elements that better fit the environment of a given organization or project.This practice was common before the advent of hybrid methodologies.The same way tailoring is worked with in agile methods.
A characteristic of hybrid project management is combining practices from methodologies on the opposite spectrum (Prenner et al., 2021).On the other hand, contradictory principles, and values that, by their very nature, should be running through the dominant part of the methodology are not typically combined in the HPM approach.
HPM is characterized by a value or ideological emptiness distinct from traditional PM and agile.It is replaced by a cold pragmatism to replace less effective elements with more appropriate ones to achieve better results.Therefore, in HPM, we cannot expect the analogy of the Agile Manifesto (Beck et al., 2001).HPM is a field where we are unwilling to accept the disadvantages of one practice in favor of a consistent value-based approach.The emptiness is a potential strength of HPM and a differentiation from only tailored agile or traditional methods.Moreover, given the dominant definition of HPM as a combination of agile and traditional methodologies, the combination of multiple only agile or multiple only traditional methods lies beyond HPM.Related to this is that existing definitions repeatedly mention the balance of chosen practices as a characteristic of HPM (Bick et al., 2018;Binder et al., 2014;Dabney & Arthur, 2019).
In addition to the questions of what the HPM is and where its boundaries lie, it is helpful to summarize what it contains.As mentioned above, previous efforts to frame HPM do not see it as a system that has adopted values or principles.Instead, they often speak of a set of adopted practices or methods.Publications often avoid explicit content or only mention the adoption of strengths.More specifically, focused definitions talk about HPM adoption and therefore being constituted by processes, practices, roles, and tools (Bagiu et al., 2020;Brown et al., 2020;Dinis et al., 2021).Some constraints even expect a specific method, for example, the stage-gate model (Cooper & Sommer, 2016).However, these isolated occurrences do not attempt a general definition of hybrid project management.
In order to fully define hybrid project management, the aspect of time or the intended target state of the methodology needs to be girded.HPM is not a framework for gradual implementation from one to another pure methodology when an organization decides to phase in a combination of practices that would be temporary.When we talk about HPM, it is intended to be a goal-based, long-term approach to project management, although this is only implicit in the definitions of HPM, and none of them states it explicitly.It is, therefore, not an alternative to introducing a new PM methodology in a big-bang way.
As noted above, despite the extensive research on HPM, it is not easy to find corresponding specific HPM methodologies and frameworks which are more widely used in practice.Therefore, it is impossible to speak of HPM as a group of methodologies.However, as the results of our review show and as this paper illustrates below, it is possible to find specific characteristics and anchors of hybrid project management as an approach to project management.
After analyzing the individual aspects, we can put their conclusions into a comprehensive definition of HPM as follows: Hybrid project management is a project management approach combining elements of traditional and agile project management to gain advantages and suppress the disadvantages of both to increase project success.It balances flexibility, effectiveness, productivity, and project control.The ability to customize the combination to the specific needs makes this approach suitable for project management in various contexts.
At the same time, the out-of-scope definition in the wording that HPM is not tailoring APM or TPM, nor is it a combination of practices within one of them, nor is it a temporary combination of practices during the transition from one approach to the other.We have depicted these PM approaches as forming what we call the project management approach continuum in Figure 3.

HPM in the VUCA World
In today's VUCA world, project management is a key competency.We analyzed the individual characteristic attributes of the VUCA concept and the affinity with individual PM approaches (see Table 6).HPM appears to be a suitable approach, which is also confirmed by surveys from recent years when this approach is rapidly gaining popularity and becoming the predominant method of project management (Digital.ai, 2021;Gemino et al., 2021).

Volatility
The change happens more often than in the past, it is faster and has a much greater impact.

No Yes Yes
Uncertainty The number of changes and their great impact means that we are working with increasing uncertainty.What is true today may not be true tomorrow.

Partly Partly Yes
Complexity Everything relates to everything.There are many non-linear connections, and it is difficult to determine simple contexts.This not only prevents us from being easy to understand, but it mainly prevents us from finding simple solutions.

Yes
No Yes Ambiguity Volatility, uncertainty, and complexity cause that there is no single truth, the only right solution.

Partly Partly Yes
Although TPM can deal with change, it is an undesired complication and deviation from the plan.On the contrary, APM embraces the change, and this feature is also carried over to HPM.
As for uncertainty, TPM partially deals with it through risk management and APM through postponing decisions until they are needed at the latest.HPM can combine both, achieving even better results.
While TPM can deal with complexity very well through decomposition and planning, in APM, too many dependencies and the need to cooperate with many resources is a problem.
In this case, HPM can maintain control of the hybrid and combine this with flexibility where possible.And finally, TPM partly helps the principle of tailoring and APM adaptive development, but in terms of methodology, both approaches present themselves as a solution that suits everyone.In contrast, HPM is an ideal example that there is no single right solution, and with "built-in" customization, it can fully cope with the challenge of ambiguity.

Recommendations for Research
Among the opportunities for further development, we see room for the further concretization of hybrid project management, specifically through exploring appropriate combinations of practices in specific settings and iteratively combining them.An additional research opportunity is to investigate the link between the project type, its implementation environment, and the appropriate form of hybrid project management.Furthermore, a view of HPM from the perspectives of project participants is missing.For example, exploring how they operate between practices that have no unifying line.

Recommendations for Practice
The use of the hybrid approach in practice is increasing.According to recent surveys, most projects already use a combination of project methodologies (Gemino et al., 2021).
Project leaders and organizations need to become familiar with this approach, know its merits and weaknesses, and apply it where appropriate.Grounding and knowing what HPM is and what it is not will help practitioners in further education and adoption of HPM in their organizations.
Firms should examine their motivation for hybrid project management.HPM is characterized, among other features, by its motivation to optimize project outputs.However, if, for example, firms mix different practices simply because they are unwilling to invest effort in full-fledged traditional management, this approach may manifest in inferior results.

Limitations
In our research, we are aware of several of its limitations.The most obvious limitation is that this field is still in its infancy compared to other areas of project management.In general, the preliminary work is limited to a subset of a few scientifically written articles and a few coherent findings.Also, there are not many empirically based studies, and those that exist are limited by field, sample size, product type, or project specifics.While existing cases are valuable and illustrate a wide range of applications, they represent only a small subset of limited relevance.
Most of the articles, especially the case studies, report positive results of using hybrid project management and connect the successful execution of projects with the choice of methodology without corresponding rigorous analysis.We, therefore, point out that publication bias must be considered.Furthermore, we are aware of the limitation resulting from the choice of keywords.In some publications, the same phenomenon can have a different label than hybrid project management.Therefore, such studies can escape our analysis despite citation searching, which helps avoid this limitation.
The inconsistent quality of individual studies is also a limitation that must be considered.
Even though the methodological rigor of some papers is shallow, we intentionally did not incorporate methodological quality as the exclusion criteria.By excluding some mainly qualitative studies, we would lose some valuable insights.At the same time, doing so would introduce the opposite constraint (Reiff & Schlegel, 2022), which we avoided following the recommendations of Kitchenham and Charters (2007).

Conclusions
Despite the growing interest in the field of hybrid project management and the strong base of existing research, we face the problem of the inconceivability of the HPM phenomenon.This is evidenced by the vagueness of definitions in the existing literature, their complete absence, and differences.This paper responds to this gap by defining hybrid project management more precisely and answering sub-questions that clarify its boundaries.These questions include what it is, what it contains, and where it ends in relation to traditional and agile management.
The conclusions of these questions may help us cultivate the project management scene and make better decisions about the appropriate approach for a given environment.This paper has defined the meaning of hybrid project management through a narrative review that analyzed the delineation of existing research on the phenomenon and a critical synthesis of it.HPM is a suitable approach to project management in the VUCA world.

Figure 3 .
Figure 3. Project management approach continuum ri d p ro je c t m a n a g e m e n t H y b ri d p ro je c t m a n a g e m e n t T a i l o r e d t r a d i t i o n a l m e t h o d o l o g i e s T a i l o r e d a g i l e m e t h o d o l o g i e s

Table 1 .
Search strings

Table 3 .
How is HPM referred to in the literature

Table 4 .
What is combined in HPM according to the literature

Table 6 .
Suitability of the PM approach