PRISMA protocol is widely accepted standard. I have attached a full text for your convenience.

Hey Gulzar Shah, indeed PRISMA protocol can help. I have been applying it as you can see in the references mentioned in the discussion statement. Thanks for attaching the text.

In case you can read German this might help you:

https://www.amazon.de/Qualitative-Marktforschung-Konzepte-Methoden-Analysen/dp/3834909769/ref=sr_1_1?s=books&ie=UTF8&qid=1539095606&sr=1-1&keywords=Marktforschung+Holzm%C3%BCller

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Regards, Jens

Okoli, C. (2015). A Guide to Conducting a Standalone Systematic Literature Review. Communications of the Association for Information Systems, 37(43). doi:citeulike-article-id:13897347

https://aisel.aisnet.org/cais/vol37/iss1/43/

Jens Uwe Pätzmann , thanks for the input. Unfortunately I can't read German, but it can contribute to part of the community.

Sean Alfred , that's a fairly comprehensive guide. It provides a stepwise approach and explains the steps to be taken in depth. The section that I found most helpful in the discussion proposed here is '8 Synthesize Studies'. In management related fields, cases are normally descriptive/qualitative and the discussion in the article can help to define strategies to combine quantitative and qualitative approaches to synthesize.

In fact, I have found some studies that combine systematic review of case studies. Here are two that fit the approach I have been applying.

Henttonen, K. (2010). Exploring social networks on the team level-A review of the empirical literature. Journal of Engineering and Technology Management - JET-M, 27(1–2), 74–109. https://doi.org/10.1016/j.jengtecman.2010.03.005

Muench, S., & Guenther, E. (2013). A systematic review of bioenergy life cycle assessments. Applied Energy, 112, 257–273. https://doi.org/10.1016/j.apenergy.2013.06.001

There are probably more studies, employing diverse approaches for case selection, data collection, analysis and so on.

If anyone happen to find such a study, please add it here so we keep discussing.

These are two interesting guides. They describe how to make a systematic review (step by step), and some chapters focus on specific fields (e.g.: qualitative, quantitative) and disciplines (e.g.: social sciences, economy).

The books are also available on Google book.

Gough, D., Oliver, S., & Thomas, J. (Eds.). (2017). An introduction to systematic reviews. Sage.

Boland, A., Cherry, G., & Dickson, R. (Eds.). (2017). Doing a systematic review: A student's guide. Sage.

I have also been on the search for SLR reporting protocols for studies that are a mix of quantitative, qualitative, and mix-methods studies within the social sciences (disasters). Pettricrew & Roberts' book, "Systematic reviews in the social sciences: a practical guide" is pre-PRISMA so I'm looking for updated perspectives. enough back story!

Tonight I dug into the equator Network (Enhancing the QUAlity and Transparency Of health Research) and it might have some examples for you to look at. I see they have some example reporting guidelines for Case Reports:

The CARE Guidelines: Consensus-based Clinical Case Reporting Guideline Development

http://www.equator-network.org/reporting-guidelines/care/

Search on Case Report:

http://www.equator-network.org/?post_type=eq_guidelines&eq_guidelines_study_design=0&eq_guidelines_clinical_specialty=0&eq_guidelines_report_section=0&s=case+report&btn_submit=Search+Reporting+Guidelines

I know it is not your discipline; however there might be examples that can be used as models.

Just a follow up, from the studies mentioned in the question, I have published the following article. In this work, we employed a systematic literature review of cases published in the literature in combination with content analysis to verify the application of specific Circular Economy strategies and obtain business practices to operationalise those practices.

It can potentially help regarding the methodology employed.

Article Circular Innovation Framework: Verifying Conceptual to Pract...