I don't know how to fix the order of page numbering for table of contents, list of figures, list of tables, and nomenclature. I use \renewcommand to change the Arabic numbers to Roman; however, for each part, the numbers start from one (i). How can I make the numbers consistent (start from i, ii, ... for the all parts)?
{\newcommand{\romantableofcontents}{ % creates a table of contents with roman (i, ii, iii, ...) numbering of the pages \newpage \pagestyle{plain} \pagenumbering{roman} \tableofcontents \pagenumbering{arabic} \pagestyle{fancy} } \newcommand{\listoffiguresnew}{ % creates a table of contents with roman (i, ii, iii, ...) numbering of the pages \newpage \pagestyle{plain} \pagenumbering{roman} \listoffigures \newpage \pagenumbering{arabic} } \newcommand{\listoftablesnew}{ % creates a table of contents with roman (i, ii, iii, ...) numbering of the pages \newpage \pagestyle{plain} \pagenumbering{roman} \listoftables \newpage \pagenumbering{arabic} } \newcommand{\printnomenclaturenew}{ % creates a table of contents with roman (i, ii, iii, ...) numbering of the pages \newpage \pagestyle{plain} \pagenumbering{roman} \printnomenclature \newpage \pagenumbering{arabic} } } 
\pagenumberingresets thepagecounter. So instead of switching toromanfor each of the lists, you should do the switching once only. But without MWE (see the link in the comment to your last question) I don't know, if this can be done in your case, or if you need to store the last roman number and restore it for the next list. BTW: Your are not using\renewcommandto change the Arabic numbering. You are using\pagenumbering.\pagenumberingcommands from the commands defined here. Just ise\pagenumbering{roman}once at the start of the frontmatter and\pagenmbering{arabic}once at the start of the main part of the document