diff --git a/SOPTving/SOPTving/Presentation/AuthScene/ViewModel/SignInViewModel.swift b/SOPTving/SOPTving/Presentation/AuthScene/ViewModel/SignInViewModel.swift
index 846bffa..3396656 100644
--- a/SOPTving/SOPTving/Presentation/AuthScene/ViewModel/SignInViewModel.swift
+++ b/SOPTving/SOPTving/Presentation/AuthScene/ViewModel/SignInViewModel.swift
@@ -6,87 +6,3 @@
 //
 
 import Foundation
-
-enum AuthError: Error {
-    case invalidEmail
-    case invlidPassword
-    case invalidUser
-    
-    var message: String {
-        switch self {
-
-        case .invalidEmail:
-            return "이메일형식을 잘못 입력하셨습니다."
-        case .invlidPassword:
-            return "비밀번호를 8자 이상 입력해주세요."
-        case .invalidUser:
-            return "존재하지 않는 회원입니다."
-        }
-    }
-}
-
-protocol SignInViewModelInput {
-    func emailTextFieldDidChangeEvent(_ text: String)
-    func passwordTextFieldDidChangeEvent(_ text: String)
-    func signInButtonDidTapEvent()
-}
-
-protocol SignInViewModelOutput {
-    var ableToSignIn: Observable<Bool> { get }
-    var isSuccessLogin: Observable<Result<Bool,AuthError>> { get }
-}
-
-protocol SignInViewModel: SignInViewModelInput, SignInViewModelOutput { }
-
-final class DefaultSignInViewModel: SignInViewModel {
-    
-    private var email: String
-    private var password: String
-    
-    //MARK: - Output
-    
-    var ableToSignIn: Observable<Bool> = Observable(false)
-    var isSuccessLogin: Observable<Result<Bool,AuthError>> = Observable(.failure(.invalidEmail))
-    
-    //MARK: - Init
-    
-    init(email: String, password: String) {
-        self.email = email
-        self.password = password
-    }
-    
-}
-
-extension DefaultSignInViewModel {
-    
-    func emailTextFieldDidChangeEvent(_ text: String) {
-        self.email = text
-        self.ableToSignIn.value = email.hasText && password.hasText
-    }
-    
-    func passwordTextFieldDidChangeEvent(_ text: String) {
-        self.password = text
-        self.ableToSignIn.value = email.hasText && password.hasText
-    }
-    
-    func signInButtonDidTapEvent() {
-        let isValidEmail = email.isEmailFormat
-        let isValidPassword = password.isMoreThan(8)
-        let isExistedUser = true //    나중에 서버 통신 후 해당 값 isExistedUser에 대입. 임시적으로 true
-        
-        guard isValidEmail else {
-            isSuccessLogin.value = .failure(.invalidEmail)
-            return
-        }
-        guard isValidPassword else {
-            isSuccessLogin.value = .failure(.invlidPassword)
-            return
-        }
-        guard isExistedUser else {
-            isSuccessLogin.value = .failure(.invalidUser)
-            return
-        }
-        
-        isSuccessLogin.value = .success(true)
-    }
-}
diff --git a/SOPTving/SOPTving/Utility/DesignPattern/Observable.swift b/SOPTving/SOPTving/Utility/DesignPattern/Observable.swift
index 3df3c52..33bee14 100644
--- a/SOPTving/SOPTving/Utility/DesignPattern/Observable.swift
+++ b/SOPTving/SOPTving/Utility/DesignPattern/Observable.swift
@@ -6,37 +6,3 @@
 //
 
 import Foundation
-
-final class Observable<T> {
-    
-    struct Observer<T> {
-        weak var observer: AnyObject?
-        let block: (T) -> Void
-    }
-    
-    private var observers = [Observer<T>]()
-    
-    var value: T {
-        didSet { notifyObservers() }
-    }
-    
-    init(_ value: T) {
-        self.value = value
-    }
-    
-    func observe(on observer: AnyObject, observerBlock: @escaping (T) -> Void) {
-        observers.append(Observer(observer: observer, block: observerBlock))
-        observerBlock(self.value)
-    }
-    
-    func remove(observer: AnyObject) {
-        observers = observers.filter { $0.observer !== observer }
-    }
-    
-    private func notifyObservers() {
-        for observer in observers {
-            observer.block(self.value)
-        }
-    }
-}
-
diff --git a/SOPTving/SOPTving/Utility/Extension/String+.swift b/SOPTving/SOPTving/Utility/Extension/String+.swift
index 1555c76..d510d3b 100644
--- a/SOPTving/SOPTving/Utility/Extension/String+.swift
+++ b/SOPTving/SOPTving/Utility/Extension/String+.swift
@@ -6,19 +6,3 @@
 //
 
 import Foundation
-
-extension String {
-    
-    var isEmailFormat: Bool {
-        let emailRegex = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,6}"
-        return NSPredicate(format: "SELF MATCHES %@", emailRegex).evaluate(with: self)
-    }
-    
-    var hasText: Bool {
-        return !isEmpty
-    }
-    
-    func isMoreThan(_ length: Int) -> Bool {
-        return self.count > length
-    }
-}