You are presented with multiple paper abstracts, alongside the associated literature review and chapter titles. Given the provided information, you are going to do a literature review. Please generate a coherent literature review that synthesizes the content, draws connections between different works, highlights major findings, and identifies any gaps in the existing research.

Literature Review Title: Software Testing Process Models Benefits&Drawbacks: a Systematic Literature Review 
Chapter Title:  Testing Models 
1. Abstract of Cited Paper (BIB001):  Software products quality is strongly influenced by the quality of the process that generated them; particularly, the testing process contributes to product quality and represents a significant effort in software development projects. In this context, this study aim to find which test process models has been defined, adapted or extended in software industry from 1990 to the current date. For this purpose, a systematic literature review has been performed according to relevant guidelines. This study has identified 23 test process models, many of them adapted or extended from TMMi and TPI, which have different architectures and the new ISO/IEC 29119 with an architectural approach aligned to other ISO/IEC software process models.

Literature Review:
The development of testing models started based on the lack of focus on testing aspects by software process improvements (SPI) models. SPI models support organizations in quality improvement of their services and products by optimizing processes of software development. To achieve this aim, several models and standards such as the Capability Maturity Model (CMM), Capability Maturity Model Integrated (CMMI) and the Software Process Improvement and Capability Determination (SPICE) have been developed over time BIB001 . One of the distinguishing features of models is their architecture. One group forms processes with staged architectures such as CMMI, where improvements are applied based on capability and maturity levels. On the other hand, standards such as ISO 9001 suggest the architecture, which specifies requirements of a quality management system  . SPI models focus on several aspects of quality improvement. However, software testing constitutes only a small part of SPI and for that reason, a number of testing improvement models has been defined specifically for testing purposes. Many of them are supplementary to SPI processes because of the similarities in their structures. Testing models help organizations to suggest and evaluate improvements of testing processes. The most popular testing approaches are Testing Maturity Model (TMM), Test Maturity Model integration (TMMi) and Test Process Improvement (TPI); moreover, they form the basis of several other existing testing standards BIB002 .