The search strategy identified a total of 169 articles. Eighty-six studies did not meet the inclusion criteria, leaving 83 studies in this review. Additional file 1 summarizes the studies.
Reasons for KM
Previous researchers suggested a number of reasons why an organization might need to consider a KM initiative, including: to help prevent possible knowledge loss (e.g., someone leaving the organization, turnover, retirement)[23–32]; to gain a greater competitive advantage [31, 33–35]; the reorganization of the company [31, 33–36]; as a formal remedy of negative findings discovered during an audit ; continuous learning ; to prevent low knowledge diffusion and/or the isolation of organizational departments, individuals, or community partners ; to coordinate with other firms/suppliers/customers ; to increase the quality of professional services,; and to help meet users' needs . Although specific reasons may vary from one organization to another, a general consensus was that KM can contribute to these sorts of organizational improvements, as well as address an array of intra-organizational problems.
KM strategies identified from the reviewed literature included: using simple mechanisms (such as training programs and seminar series), using technology, using frameworks or process-based models (including concept mapping), and using communities of practice to capture and share knowledge.
Simple mechanisms, including training sessions, workshops, mentoring/apprenticeships, and interviews, were implemented in 6 studies [2, 24, 28, 32, 42, 43]. Some of the training programs were virtual or web-based , however, others were delivered face-to-face because many believe this to be an essential component of training programs . Implementing a seminar series was another dominant KM approach; for example, a specialized "Leaving Expert Debriefing", where managers and/or employees are interviewed by their peers with the goal of retaining the knowledge of "experts" who are planning to leave their current organization . Other seminar series included a number of classes where group work, problem solving, and coaching occurred in interactive settings [28, 32].
Despite the various definitions of KM, almost everyone agrees on the significant role technology has in KM. In fact, KM is frequently positioned as being comprised mainly of efficient and effective information technology (IT) and ICT systems [26, 27, 44, 46–48]. For this reason, using technology systems(and communication technologies) is a key element that may be incorporated into KM initiatives. While details of each technical system vary, the overarching purpose of technology systems is to organize, codify, distribute, and maintain knowledge resources . The predominant focus of many KM strategies is on technology and management of explicit and tacit forms of knowledge.
Other organizations described in the literature designed KM strategies around conceptual frameworks or process-based models[1, 2, 31, 37, 40, 49–59]. The majority of these frameworks/models included stages to attain, or replicate KM strategy development. One such study featured a roadmap that included an inner layer (the KM system backbone: the strategy, sharing, storage, identification, and audit of knowledge); a middle layer (necessary success factors: business-process re-engineering, piloting strategies, organizational structure, training programs); and an outer layer (factors for successful establishment of all systems in the organization: organizational culture, CEO/executive support, transparency, and trust).
Another framework introduced the concept of mappingout knowledge, routines, capabilities, and inertia as a tool to advance KM in an organization or unit. The fundamental idea behind this is that latent resources (dormant, but capable of development) are mobilized by endogenous (managerial) or exogenous (legislative/environmental) elements, and that different ratios of active to latent resources, routines and capabilities can have different degrees of adaptability. In stable contexts, organizations that are more adaptable will also be more flexible and responsive, whereas less adaptable organizations are more "lean" (or efficient) but have a limited portfolio of resources to draw on (i.e., more prone to the status quo). Others have used the mapping concept (e.g. "Capabilities Map", and "Levels of Learning Progression Map") as a process that can capture knowledge-oriented practices .
Another concept often considered a useful KM strategy, and heavily discussed in the literature, is Communities of Practice(CoP)[62–69]. Communities can vary in format (virtual/face to face), and Chua  argued they have three main underlying structures:
Domain (the sphere of knowledge and expertise held by members)
Community (relationship, affinity, and the sense of belonging among members)
Practice (the common set of frameworks, ideas, and tools members share in their work context)
The objectives of the CoP should be aligned with the host firm's strategic purpose . Each CoP should have a Leader or Moderator who spearheads defining the objectives of the CoP and maintaining the focus of the community [65, 68]. In addition, there is a Core Team who assists the Leader by developing activities and workshops in collaboration with the Leader . The active members each bring their own role, knowledge and expertise to the community [65, 68].
Communities may extend past institutional boundaries through online CoPs, an especially important strategy for small organizations to extend their reach . However, it may be difficult to create and sustain online those CoPs with the purpose of knowledge creation as the technology and social structure involve much effort . Moreover, organizations may experience less control over online CoPs outside of their organizational boundaries . Therefore, online CoPs may not be appropriate to address every organization's KM needs.
The literature demonstrates that a one-size-fits-all KM solution may not be achievable or desirable. Organizations may need to invest some time to identify their needs and reasons for employing KM practices, and to ensure that they have the resources (e.g., financial, personal, technical) to support their desired strategy. Identifying possible KM facilitators and barriers may assist various organizations in recognizing whether they are capable of successfully implementing a KM solution or strategy.
KM Facilitators and Barriers
Since most of the studies included in this review were based on a single case of KM, it is inappropriate at this point to come to any conclusion about which strategies are more effective than others. Instead, we present the common facilitators and barriers to KM initiatives that surfaced across studies.
Commonly cited KM facilitators include: organizational culture, organizational structure, management and champion support, design of KM strategy, performance/evaluation, and training, which are all further explained in this section.
Thirteen studies indicated that KM can be facilitated by an organizational culturethat is horizontal or flat in structure, with very few or no hierarchy levels [5, 29, 36, 40, 62, 68–75]. These same studies also put forth that an organization should emphasize the importance and value of people as a main resource, encourage teamwork, and enable knowledge sharing. Further, it is argued that there needs to be a 'knowledge creating and sharing culture'[76, 77] with trust and openness at the organization's core [5, 35, 44, 78–81]. Organizations that have shared common values and culture have an advantage when implementing a knowledge management system (KMS). It is beneficial to use cross-functional organizing, that is, to draw upon expertise regardless of where it may lie within the organization . Physical attributes, such as the configuration of the work environment (i.e., close desk proximity has been associated with more knowledge sharing) influences the knowledge sharing culture in organizations and can contribute to the KM initiatives' success . Also, the delivery channel (for example, intranets, e-mail, internal magazines, meetings, notice boards, etc.) should be selected based on its suitability in relation to the organizational culture of the company .
Organizational structureis closely associated with organizational culture and structures and can facilitate collaboration . There is currently not unanimous agreement or understanding of a Human Resources (HR) department's role in KM; for example Oltra found that the HR department should be separate from the KM system , while Hsu found it an asset to have HR involved in the development of a KM system . In other words, HR involvement may be fundamental, or completely unnecessary to KM development, depending on the organization's structure, needs, goals and preferences. Oliver and Kandadi suggested allocating appropriate amount of time for employees' learning, collaboration, knowledge creation, and sharing activities as a fundamental structural consideration . Some authors suggested that organizations may require a whole new organizational structure, which would have conventional structures transformed to support a knowledge culture [82, 83]. For example, it might be important for an organization to develop a common language (or, an 'organizational thesaurus') to ease the communication within the organization .
Many of the studies indicated that management support, including a strong, consistent, and more importantly, cohesive promotion of KM is important to the success of a KM system . Executive involvement and support needs to be built into the KM initiative in order to ensure success [2, 5, 40, 44, 46, 61, 62, 67, 72, 74, 76, 79, 81, 84]. Having a champion(i.e., a very influential individual within an organization who supports KM)[23, 28, 85, 86] in combination with strong KM leadership [29, 76, 82] was frequently acknowledged as an important facilitator. Recruiting employees with a positive attitude towards knowledge sharing and team dynamics , and developing relationships with pertinent individuals , is important for successful KM. For example, Hofer-Alfeis argues that to bridge the gap during a transition of power, it is important to promote a relationship between the leaving expert and their successor .
Another facilitator for successful KMS was a clear and concise KM framework or design. Plessis noted that the KMS should be linked to the business strategy, and the approach to KM should be holistic with flexible structures, and adaptable to the business environment changes . Human-related factors, or interpersonal interactions, such as face-to-face contacts and close physical proximity, are fundamental to the success of KM initiatives [5, 69, 80, 87–89]. The KMS needs to include processes to help provide standards for KM initiatives and ensure roles and responsibilities within the initiative are clearly defined . Many successful KM systems integrated monetary and non-monetary incentives (such as rewards and recognitions) to encourage the implementation and adoption of KM initiatives [5, 25, 47, 69, 75, 76, 81, 82]. Managing knowledge throughout its lifecycle is important (for example, knowledge repositories regularly updated, improved, and fostered in a way to improve decision making) and the process of knowledge sharing should occur continuously throughout the time of employment, not just when someone leaves the organization . Further, the collection of both explicit and tacit knowledge was cited as a KM facilitator .
Trainingthat provides a complete and in-depth understanding of how KM works may motivate employees to assist in KM strategy development [40, 76, 90]. It is especially important that employees are trained in how to use supporting technologies, especially for KM initiatives with a predominantly IT-based focus . Also, employees need time following the implementation of a new KM initiative for reflection and learning purposes .
Other facilitators included: perception of the KM system being important, along with encouraging buy-in at all levels by promoting KM as a strategic initiative ; recognition of the impact of communication (structured, formal, and informal); on-going motivation for the KMS ; the presence of a clear positive benefit ; the quality of the knowledge exchanged ; a process based on realistic expectations ; and KM has to be cultivated and nurtured (i.e., not a push strategy or a coercive task).
The barriers discussed in the 83 studies can be classified as individualor organizationalbarriers.
At the individual level, change, whether in management, ownership, or employee turnover, can be a source of distress and as such a barrier to KM [37, 61, 85, 91]. Information overload can also pose a barrier to effective KM [49, 88, 91]. Individuals themselves can be barriers to effective KM if they are unqualified, inappropriate authorities (such as individuals who are in a position of power without the appropriate KM training, understanding of its purpose, etc.), resistant to change [6, 26, 71, 84, 92, 93], or have insufficient technology skills [6, 84, 93]. Discussing problems, sharing, or thinking out loud may not come naturally to some, and as such can pose a personal challenge , which may also be detrimental to a KM system, since knowledge sharing is a fundamental component of KM. Individuals may lack motivation to implement a KM initiative because of minimal incentives/rewards, time, or desire [5, 49, 78, 79, 87, 91]. In addition, the loss of a KM champion can devastate the initiative . Lack of support from management and/or employees can pose as a significant barrier to full participation of employees [6, 45, 50, 51, 67].
Barriers to KM implementation and success at the organizational levelinclude both organizational culture and structure [5, 25, 46, 51, 60, 62, 68, 69, 71, 79, 94]. More specifically, a top down approach , separate departments [31, 40], lack of "ask why" thinking , lack of trust , and not being open to sharing knowledge and information such as "lessons learned" can impede KM efforts. The time and money that it can take to implement a KM initiative may discourage employees from even attempting to develop a KM system [23, 50, 85, 95, 96]. Furthermore, it can be difficult to present an observable (or immediate) benefit (i.e., it may take a long time to really see the positive changes contributed by the KM strategy), which may result in the KM concept being viewed as not valuable or not worth the effort/resources needed . For an organization that is heavily invested in technologies, barriers to successful KM may include inconsistencies, malfunctions, or software incompatibility, as well as the challenge of obtaining the software for the knowledge base and a lack of balance between IT and personal interaction [23, 30, 37, 51, 68, 78, 87, 88, 97, 98].
The intangible element associated with knowledge (e.g., "managing stuff in people's heads"), and the nature of organizational learning [5, 61, 66, 92], along with having no standard KM definition are all serious barriers to the success of KM initiatives [23, 30]. A lack of clarity about the measurement of KM processes can also hinder KM initiatives [44, 45, 61, 68]. For example, having little or no clear strategy or guidance on how to capture and store important explicit knowledge, or how to translate tacit knowledge into explicit knowledge, or how to evaluate the initiative can present a serious barrier to effective KM [25, 30, 99].
Disagreement or conflict can present a challenge for KM. For example, if employees have differing goals, or goals that are at odds with the overall KM purpose, this can lead to resentment between middle management and front line workers (for example due to increased work load from KM implementation)[6, 23, 34, 35].
Additional barriers identified less frequently in the review of the literature included concerns regarding implementation of KM initiatives. One such concern includes ensuring enough time (i.e., approximately one year) prior to planning a KM processes and beginning the search for a successor, commencing the KM process (e.g. leaving expert debriefing) early, and hiring a successor before starting the KM strategy allowing him/her to learn from the leaving expert . Furthermore, monetary rewards can potentially create unfriendly team environments, resentment, competition and loss of focus of the overall KM purpose . Also, one should be aware of over-management and interference from the political sphere trying to force KM to occur prior to considering a KM initiative .
To summarize, some individual-level barriers can be overcome, such as training or allocating adequate time for KM work. Organizational environments that downplay reporting hierarchies in favour of openness and a shared culture are more favourable to KM strategies. While management support is crucial for success, the need for support from human resources departments is not conclusive. Another important consideration is a clear KM framework or strategy that incorporates human factors (e.g., rewards, face to face time). Finally, the challenges that accompany IT need to be addressed - for example, rapidly evolving technology that demands adaptation, or difficulties in using IT infrastructure in a way that is appropriate for the organization's needs .