# How to Optimize the Implementation of ITIL through a Process Ordering Algorithm
## 2 State of Art
### Strategies and Critical Success Factors  
(a) Critical success factors: Another research area is composed by those authors who try to identify success factors on ITIL implementation: [14; 33], where a survey is used to get info about success factors of ITIL implementation in different companies. Another example can be found in [34], where specific success factors are analyzed: Management involvement, organization commitment and effectiveness, and key factors to implement the ITIL.  
It is possible to identify also a group of works that provide methodologies and strategies to implement the ITIL [16]: It analyzes the steps to consider when implementing the ITIL (taking in consideration four big companies). From this experience, success factors are defined to a proper implementation of ITIL. It also proposes to start with the Incident Management process, but it does not show any sequence from this starting point.  
A different view is proposed in [35], where success factors indicate tools and management as key elements. It is explained how the success does not depend on the sequence but on the software and tools use to a proper management of the implementation task. This point is also addressed by [36], where software tools (mainly BPM) are critical for success.  
A compilation work can be found in [18]: An excellent systematic review of success factors and a methodology based on AHP (analytical hierarchical process) are proposed. AHP is a model to evaluate, average, and eliminate inconsistencies among a group of expert opinions.  
A vast, extensive work is presented in [34]. In this case a set of success items are presented (mainly they are like those ones in the works indicated before) but compared with more than 160 companies (although--as it is indicated in the publication--it suffers limitations due to geographical issues).  
A methodology based on business process change (BPC) is explained in [15]. BPC is used to determine the success factors, although there is nothing about the sequence of processes. A different approach can be found in [37], where failure factors are described: In fact, they are factors that may make the ITIL implementation difficult.  
(b) Strategies: Regarding strategies, [8] show how to select processes, but without any sequence. This work proposes a model in which the ITIL processes are classified de-pending on the issues such as infrastructure, resources, actions, and so on. As an alternative, [38] presents a work to define a procedure that may ease the implementation: The rule is based on the level of maturity of the organization for every task. A similar idea is presented in [39], as it also highlights the importance of maturity to decide the processes to be implemented according to objectives, practices, inputs and outputs. Something similar is shown in [40].  
In [1], the proposal just indicates the existence of two implementation strategies: One for very small companies and another one for aged companies, but without mentioning anything about the sequence. Finally, a multiagent architecture proposal can be found in [41] (it does not attend for the sequencing problem).