Remove indentation

Question

How can I remove indentation between enumeration and text? I tried \noindent but it didn't work.

    \documentclass[12pt]{article}
    \usepackage[utf8]{inputenc}
    \usepackage{graphicx}
    \usepackage[left=1.27cm,right=1.27cm,top=0.7cm,bottom=1.3cm]{geometry}
    \usepackage{fancyhdr}
    \usepackage{enumitem}
    \setlength{\parindent}{0pt}
    \usepackage{xcolor}
    \def\Date{22/03/22}
    
    \begin{document}
    \begin{enumerate}[label=\Alph*]
        \item   \textbf{Introduction}
        \begin{enumerate}[label=\arabic*.]
        \color{gray}
        
        \item   Purpose
        \vspace{0.5cm}
        
        \color{black}
     This procedure describes the risk management method that must be applied: 
        Within the framework of the processes control,
        Within the framework of the process of product realization.
    
    The Quality System Risk management is a systematic process for identification, assessment, control, communication and review of risks to the quality system processes. It is just acknowledging that risk happens, and taking measures to ensure we are completely prepared for it.
    
      \vspace{0.5cm}
    \color{gray}
     \item  Field of application
     
    \color{black}
      \vspace{0.5cm}
    This procedure applies to all process and product risk analyses conducted within DiappyMed. 
    
      \vspace{0.5cm}
    \color{gray}
     \item  Definitions
       \vspace{0.5cm}
       
    \color{black}
    \textbf{Risk Analysis}
    Use of available information to identify hazardous phenomena and estimate the risk
    
    \textbf{Damage}
    Physical injury or damage to the health of persons, or damage to property or the environment
    
    \textbf{Severity}
    Measure of the possible consequences of a dangerous phenomenon
    
    
    \end{enumerate}
    \end{enumerate}
    \end{document}

Answer 1

By use of the modified description list as suggested @Marco Daniel answer in your case enable to write a bit shorter and simpler code:

\documentclass[12pt]{article}
\usepackage{geometry}
\usepackage{enumitem}
\newcounter{descriptcount}
\usepackage{xcolor}

\setlength{\parindent}{0pt}

\begin{document}
\begin{enumerate}[label=\bfseries\Alph*,wide]
\item\textbf{Introduction}
    \begin{description}[before={\setcounter{descriptcount}{0}},%
                        font=\color{gray}\normalfont%
                             \stepcounter{descriptcount}\thedescriptcount.~,
                        topsep=5mm,itemsep=3mm,parsep=3mm,
                        wide
                             ]
        \item[Purpose]~

        This procedure describes the risk management method that must be applied:
        Within the framework of the processes control,
        Within the framework of the process of product realization.

        The Quality System Risk management is a systematic process for
        identification, assessment, control, communication and review of
        risks to the quality system processes. It is just acknowledging
        that risk happens, and taking measures to ensure we are completely
        prepared for it.

        \item[Field of application]~

        This procedure applies to all process and product risk analyses
        conducted within DiappyMed.

        \item[Definitions]~

        \textbf{Risk Analysis}
        Use of available information to identify hazardous phenomena
        and estimate the risk

        \textbf{Damage}
        Physical injury or damage to the health of persons, or damage
        to property or the environment

        \textbf{Severity}
        Measure of the possible consequences of a dangerous phenomenon
    \end{description}
\end{enumerate}
\end{document}