Intrinsic and Extrinsic Factors Associated with Succession Planning and Management (SP&M) Process: A PRISMA Systematic Review

Aims: This review aimed to systematically assess the findings of primary studies to identify the intrinsic and extrinsic factors associated with succession planning and management (SP&M) process according to the PRISMA systematic review. Background : There is evidence of several related factors and gaps that still exist in understanding the differences between intrinsic and extrinsic factors which influence succession planning and management process within contexts. Design: Systematic review with narrative summary. Data Sources: Scopus and Google Scholar databases were used to identify original studies that discussed the factors associated with succession planning and management (SP&M) process between 2010 and 2020. Results: A total of 73 studies were selected for this review. Intrinsic factors dealt with social identity and leadership competency, whereas extrinsic factors dealt with organizational culture and management support. These were the most frequently reported factors associated with SP&M. Conclusion: Both intrinsic and extrinsic factors play an essential role in succession planning and management (SP&M) process. Future research should use more robust research methods and pay more attention to contrasting sectors and industries as the nature of the businesses is different. Impact: This review discussed the factors associated with succession planning and management (SP&M). The findings linked several intrinsic and extrinsic factors to SP&M. Hence, businesses should search for a perfect blend of intrinsic and extrinsic factors based on needs and organizational commitment to improve SP&M process. This is because more organizations are discovering that SP&M has gained much importance while organizations fight to attract and retain talents. Therefore, succession planning has become a vital tool to retain the best hires.


Introduction
The business world, in general, is going through a difficult period and becoming more demanding and competitive. In this unpredictable, challenging market world, companies must persevere and thrive by taking on new challenges (Pati & Das, 2018). Therefore, every organization needs to come up with different strategies and work continuously to stay in the market (Miah & Adha-Hafit, 2019), To achieve positive outcomes and competitive profits, the organization has to enhance successors with skills. These successors are those who will do their best on their jobs (Aguenza & Som, 2018). Change is inescapable, and leadership changes will happen in any organizations. Many variables can cause uncertainty in the workplace. These include retirement, attrition, illness or finding better jobs (Maphisa et al., 2017).
Drawn from the human resources literature, Opute (2020) concluded that managing the employee talents attracts many connotations and approaches. One of them is succession planning and management (SP&M). Researchers have also found that the most pressing issue facing organizations today is succession planning (Ishak & Kamil, 2016). Atwood (2020) revealed that more organizations have started to acknowledge the importance of SP&M while they fight to attract and retain talents. Thus, succession planning has become a vital tool to retain the best hires. Today, succession planning is not just a process to replace the upperechelons 1 , but also a necessity for leadership at every level of an organization (Atwood, 2020). Baker (2017) found that ineffective selection and preparation of the upper-echelons within an organization often cause adverse effects due to the criticality of the succession planning problem in organizations. So, it is necessary to be in the know of the current trends and statistics surrounding succession planning. By doing so can increase one's awareness of the necessity for studying succession planning. Therefore, Atwood (2020) mentioned in his book that succession planning can only be succeeded by producing qualified candidates that suit certain key positions when an available vacancy occurs. Likewise, succession planning can ascertain that a specific department of a company is aligned with the recent strategic planning and mission of the organization.

Background
Even though the succession planning and management (SP&M) process is embryonic, it is indeed a critical element in an organization with regards to sustainable strategies. This process can provide high performing employees with development opportunities and career advancement prospects (Damer, 2020). Additionally, succession planning is a mechanism of talent retention initiative which supplies organizations with a supportive pool of talents that support the organization, develop sustainable performance and improve competencies (Al-Shamsi et al., 2015;Al-Haddad & Kotnour, 2015). Nevertheless, the overall problem is due to the lack of leadership in the development and succession planning within the companies, particularly in having inadequate strategies for generating and retaining future successor generation, and preparing them to accept roles within the organizations (Damer, 2020). All these are affecting the morale of local managers who get limited opportunities to take on higher positions in the companies.
We discovered several reviews of factors related to SP&M process were carried out over a decade ago from various sectors, such as higher educations, non-profit organizations, Small-Medium Enterprises (SMEs), hospitals, government institutions, banking, Family-Owned Businesses (FOBs), automobiles and public sectors (Ali et al., 2019;Bokhari et al., 2020;Santhanalaxmi & Chandramohan, 2019;Torabi et al., 2019;Ahmad, 2018;Pandey & Sharma, 2014;Mehrabani & Mohamad, 2011). However, no systematic assessment of the differences and similarities between factors related to the SP&M and various settings (context) had been found. Therefore, the research question used to guide our study was: What are the intrinsic and extrinsic factors associated with SP&M process?

Aims
To fill the gaps and provide an updated comprehensive review of the latest development, the present study reviewed published articles in the period of 2010-2020. In particular, the main purpose of this study was to provide a systematic review of research assessing the factors influencing SP&M. The study also aimed to identify the differences and similarities of SP&M in various settings using previous frameworks as the basis to track the changes and indicate future research areas and directions.

Review Methods Protocol and Registration
To report and examine study biases systematically, we used the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) which is a recognized method of reporting reviews that makes use of a 27-item checklist developed for transparent reporting of research findings (Liberati et al., 2009). Based on the review aims, a preview protocol was developed to guide the literature search which contained information of the search terms, databases and screening criteria (Yang et al., 2017).

Inclusion and Exclusion Criteria
The article had to meet pre-defined criteria. The criterion for the selection of the papers was that the articles had to be full-length and published in English between 2010 and 2020. Thus, all other publications such as research notes, editors' comments, readers' comments and book reviews were included. This review also considered any organization and industry which had undergone a tremendous change over the last decade, especially organizational working environments. New technology, as well as economic and demographic changes usually shape the challenges of SP&M process. So, analysis of studies conducted in this period could improve the understanding of changes involving the factors in ensuring leadership continuity and building talents from within. We, therefore excluded studies carried out before 2010.

Search Methods
An extensive literature search was conducted using two main databases such as Scopus and Google Scholar. Therefore, the citations from the identified articles were traced between January 2010 and December 2020 (see Table 1 for search terms). The results and references were then analyzed for potential overlooked studies of interest which explored 'article title, abstract, keyword' of every published document in this field.

Study Selection
All authors independently selected papers to be included in the journal. Any disagreement regarding their inclusion was then resolved through a consensus.

Data Collection Process
The authors then perused the articles and subsequently performed a content analysis. Any conflict was resolved through discussions among the researchers until a consensus was achieved. A single researcher (Don) then carried out a thematic synthesis to identify relevant data and extract their contents using a template. The data were only extracted from texts labelled as "results". Subheadings were added as the data were collected and themes emerged. Another researcher (S.K) reviewed the data and further identified themes and subheadings in a synergistic process. Most of the studies did not specifically mention in the report of their findings the factors associated with SP&M. The researchers merely inferred barriers and facilitators to SP&M from the views and experiences of the study populations.

Data Items
Every article was carefully read and information of research themes/focuses, methods and author/s was recorded on an Excel sheet. To determine whether the findings were internally coherent and relevant to the aims of the study, they were assessed based on the various research aspects, such as method of data collection, record keeping, data analysis and the researcher's role in the study.

Study Selection
Entering the "succession planning" keyword as the search criterion resulted in 3,211 fulllength articles published between January 2010 and December 2020 being retrieved using Scopus and Google Scholar as a database strategy. After being identified, the total record articles after duplicates had been removed were 1,242. Next, these articles were screened and 732 articles excluded due to no abstract available. The "succession planning" term was also used in different areas, such as sustainability, ecological, environment planning and natural hazard. Only 257 full-text articles were thoroughly read and assessed for eligibility. Further 34 of the retrieved articles were excluded as they were unrelated with reasons such as the articles are only guidelines, abstracts or opinions. Then, 223 articles were reviewed once again thoroughly for qualitative synthesis. A review of the full-text remaining studies resulted in further 150 studies being excluded based on the inclusion and exclusion criteria. Also, two studies were excluded as unobtainable. The selection process was performed by two reviewers who worked independently. Discrepancies and disagreements were resolved by discussion (see Figure 1 for the PRISMA flow diagram).

Data Abstraction and Synthesis
Data extraction was completed using a form based on the Cochrane Consumers and Communication Review Group's data extraction template (Ryan & Hill, 2016). The data extracted for this review were as follows: author, year, journal title, country, research purpose, theoretical framework, design, setting, subjects, samplings method, relevant sample characteristics, response rate, measurement instrument, independent and dependent variables, and key results of the study.
Data were extracted into summative tables using an Excel spreadsheet. Selected studies were represented in rows, with data items in columns. This technique helped with extraction of information from each study and therefore reduced time and effort needed to identify similarities and differences. Relevant data were extracted using content analysis where the spreadsheets were reviewed and identified factors were coded. The identified SP&M factors were reviewed for frequency, similarities and differences before being categorized.
For consistency, we adopted a standardized scoring approach for SP&M that was used in a previous systematic review where different tools were also used to measure SP&M across the reviewed studies (Dilig-Ruiz et al., 2018). Finally, where possible, we compared the factors influencing SP&M in different settings based on the reported findings. Meta-analysis was not used for the review as selected studies were considered too heterogeneous in term of methods and analysis, and thus a more descriptive approach was suitable. Disagreements between reviewers were resolved by discussion.

Study Characteristics
Seventy-three (5.88%) from 1,242 studies were included in this review. It was reported that majority of the studies were conducted in the United States (N=16), Europe (N=9), Africa

Synthesis Results
This study reviewed on the factors associated with succession planning and management (SP&M) process between 2010 to 2020.

Intrinsic Factors associated with Succession Planning and Management (SP&M)
Thirty-one of the studies included in this review reported that social identity was associated with SP&M, making it the most frequently linked intrinsic factor. Social identity is generally related to an individual's own perception of self, based on his or her connection in a group such as ethnicity, race or gender (Gangadharan et al., 2020). A person's social identity indicates a set of rules that controls group behavior. Hence, it identifies behavioral differences across groups. There seems to be a growing interest in research exploring how, especially gender, personality, demographics and nationality can affect succession and business strategies. For example, comparative studies have been found exploring gender and family business ownership across countries (Gause, 2021;Glover, 2014 . Luan et al. (2017) revealed that a family business is more likely to select an insider as the new successor when the incumbent successor is a family member. However, in a different setting, the finding suggested that family involvement in business operation is not necessarily an indicator of successful performance of the family business, as it could have both advantages and disadvantages (Chirapanda, 2020). Meanwhile, nine studies mentioned the importance of knowledge transfer associated with SP&M to ensure continuity, allowing organizations to preserve institutional knowledge. Someone at the top must lead the way to create a culture of sharing, as well as formal and informal structures for communication pathways (Boyd et al., 2015;Letonja et al., 2021;Parker et al., 2017;Santhanalaxmi & Chandramohan, 2019).
Another most studied intrinsic factor was diversity, acknowledging that employees from various backgrounds have enriched the organization's culture, which could possibly engender appreciation of differences. Therefore, a better of understanding of the different talents and abilities can help with the training of future successors (Kumaran, 2015;Sanchez-Rodriguez, 2020;Virick & Greer, 2012). Although some studies addressing diversity had used a broader approach by including race and ethnicity, very few emphasized on implications for women or the minority group as less favorable to be nominated as successors (Kwan & Shen, 2015;Kumaran, 2015;Virick & Greer, 2012). Another study done by Balasen and Balasen (2016), which referred to Davenport and Harding (2010); Kelly and Nadler (2007), as well as Hales (2006), suggested that lower level managers should be allowed to use repertoire of roles flexibility and focus on influencing processes and decision rather than controlling them. It is believed that empowerment is one of the keys to inspire people, increase their performance and improve their leadership capacity (Balasen & Balasen, 2016).

Extrinsic Factors associated with Succession Planning and Management (SP&M)
Among all of the extrinsic factors that have been studied, management support is the most discussed in 17 studies, for instance, Mehrtak et al (2014) in health-system pharmacy departments. They suggested that internal commitment programs to be included actively in promoting from within, a robust residency program, transparency in succession planning and support for advance degrees. One of the categories mentioned in the research finding by Bazneshini et al (2020) is managerial factors, which include the managers' support for succession planning and their commitment (Phillips, 2020). Similarly, with the FOB, when there is more trust between the owner-manager and the successor, as well as a warm and mutually supportive relationship between them, the more they will share the responsibility for perpetuating and enhancing family assets (Maciel et al., 2015).
Previous studies have highlighted the need for organizational culture to ensure that the organization has successful succession planning strategy (Arham et al., 2021;Al Suwaidi et al., 2020;Ahmad et al., 2020). The results showed that succession planning strategy, organization culture and leadership development opportunities were the most significant factors (Al Suwaidi et al., 2020). This suggests that successful succession planning strategy must be aligned with the organizational culture.
Furthermore, one of the various extrinsic factors that influenced SP&M is to facilitate an environment which fosters professional growth and clarifies career path by training and development, mentoring and coaching, as well as talent management. In the study, they found that in-house training can help employees acquire new skills and enhance knowledge, thus elevate their career progression (Arham et al., 2021;Sanchez-Rodriguez, 2021;Santhanalaxmi & Chandramohan, 2019). Training and development should involve all managerial levels to achieve the goal of developing as many talents as possible to strengthen the SP&M process. Additionally, mentoring and coaching are also integral to succession planning. Most studies advised the necessity to include coaching or mentoring as part of succession planning, such as (Moreno and Girard, 2019). The human resource professionals agreed with the various themes and concepts covered in the literature about leadership coaching (Sherrer & Rezania, 2020). However, the authors were also surprised by the scarcity of research on the actual effectiveness of this method even though coaching and mentoring are effective too for developing and implementing a succession plan. Besides that, talent management is also a factor associated with SP&M. This factor is a process that aims to ensure that the company's future leaders are equipped with the necessary skills and knowledge to lead (Pawirosumarto & Wahyudi, 2019). The talent management process is carried out to make sure the main positions are filled by internal individuals comprising a group of highly qualified human resources (Pila et al., 2016).

Discussion
The objectives of this systematic literature review were to reconcile the findings of primary studies to identify the intrinsic and extrinsic factors that were associated with SP&M process between 2010 to 2020. The results revealed five intrinsic factors and ten extrinsic factors. There was not much variety of literature available on factors which influence or are associated with succession planning and management. This is evident by the small number of studies available for inclusion in the study. Only 73 studies were found in relation to SP&M from two main sources which are Scopus and Google Scholar. Most of the studies fell under literature items such as working paper, reports, journals and reviews. Meta-analysis was not used for the review as selected studies were considered too heterogeneous in term of method and analysis, and thus a descriptive approach was deemed more appropriate. The lack of published work on the topic is an important note. Even though the results indicated that there was interest in the topic, only a few academics properly examined this topic, especially on factors.
The literature on the topic of factors is limited due to its focus on descriptive method and not enough to provide a comprehensive analysis on the effect of factors on SP&M. Too few studies have indicators of positive or negative effects on the SP&M. To gain a deeper understanding of the relationship between intrinsic and extrinsic factors and SP&M, there is a need to define the constructs for measuring the impact and develop those that allow for examining the relationship quantitatively. Furthermore, in the literature being studied, we observed an inconsistency whereby more than half of the articles did not conceptualize intrinsic and extrinsic factors, but rather a combination of both.
The most commonly investigated factor was social identity, especially gender, personality, demographics and nationality that can affect SP&M process. Most industries that applied SP&M were from FOB, academic and nursing. While our review is believed to be the first that associated intrinsic and extrinsic factors with SP&M, our findings were consistent with other reviews. For instance, Bazneshini et al. (2020) found several components that are related with SP&M, such as cultural factor, managerial factor, personal competency and managerial competency.

Limitations
Although this review was based on a systematic and validated procedure, it has some limitations. Firstly, the articles were extracted from only two main sources, which are Scopus and Google Scholar publications. In fact, only studies from the past one decade were covered. Furthermore, only three major industries such as FOB, academic and nursing were discussed. Lastly, the selected studies were too heterogeneous in terms of method and analysis. Thus, the measurement tools for predictors and outcomes were varied and their validity and reliability were not always reported. This might affect the internal and external validity of the studies.

Conclusion
Many published studies discussed the factors believed to be associated with SP&M. Although our review was able to identify several key factors, more studies using a more robust methodology are needed to examine the impact of these factors on SP&M process. There is still a gap in research about the differences between intrinsic and extrinsic factors affecting SP&M process. In order to advance in this field, first, more work is needed to conceptualize intrinsic and extrinsic factors' effectiveness and develop scales for measuring the phenomenon in the context of SP&M. Secondly, the researcher should focus on hypotheses relevant for theory development. Moreover, there is a need to diversify the methodology, both quantitative, qualitative or mixed approaches, to study questions related to the context, mechanisms and outcomes of SP&M.

Funding
I, Muhammad Afnan, on behalf of Sree Kala Kunju and Ruth Sabina, verify that we have no affiliations with or involvement in any organization or entity with any financial interest or nonfinancial interest in the subject matter or materials discussed in the manuscripts.