diff --git a/package-lock.json b/package-lock.json
index a025f74..377e71c 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -264,11 +264,11 @@
       "integrity": "sha1-ibTRmasr7kneFk6gK4nORi1xt2c="
     },
     "bcrypt": {
-      "version": "4.0.1",
-      "resolved": "https://registry.npmjs.org/bcrypt/-/bcrypt-4.0.1.tgz",
-      "integrity": "sha512-hSIZHkUxIDS5zA2o00Kf2O5RfVbQ888n54xQoF/eIaquU4uaLxK8vhhBdktd0B3n2MjkcAWzv4mnhogykBKOUQ==",
+      "version": "3.0.8",
+      "resolved": "https://registry.npmjs.org/bcrypt/-/bcrypt-3.0.8.tgz",
+      "integrity": "sha512-jKV6RvLhI36TQnPDvUFqBEnGX9c8dRRygKxCZu7E+MgLfKZbmmXL8a7/SFFOyHoPNX9nV81cKRC5tbQfvEQtpw==",
       "requires": {
-        "node-addon-api": "^2.0.0",
+        "nan": "2.14.0",
         "node-pre-gyp": "0.14.0"
       }
     },
@@ -2044,6 +2044,11 @@
       "integrity": "sha512-nnbWWOkoWyUsTjKrhgD0dcz22mdkSnpYqbEjIm2nhwhuxlSkpywJmBo8h0ZqJdkp73mb90SssHkN4rsRaBAfAA==",
       "dev": true
     },
+    "nan": {
+      "version": "2.14.0",
+      "resolved": "https://registry.npmjs.org/nan/-/nan-2.14.0.tgz",
+      "integrity": "sha512-INOFj37C7k3AfaNTtX8RhsTw7qRy7eLET14cROi9+5HAVbbHuIWUHEauBv5qT4Av2tWasiTY1Jw6puUNqRJXQg=="
+    },
     "natural-compare": {
       "version": "1.4.0",
       "resolved": "https://registry.npmjs.org/natural-compare/-/natural-compare-1.4.0.tgz",
@@ -2086,11 +2091,6 @@
       "integrity": "sha512-1nh45deeb5olNY7eX82BkPO7SSxR5SSYJiPTrTdFUVYwAl8CKMA5N9PjTYkHiRjisVcxcQ1HXdLhx2qxxJzLNQ==",
       "dev": true
     },
-    "node-addon-api": {
-      "version": "2.0.0",
-      "resolved": "https://registry.npmjs.org/node-addon-api/-/node-addon-api-2.0.0.tgz",
-      "integrity": "sha512-ASCL5U13as7HhOExbT6OlWJJUV/lLzL2voOSP1UVehpRD8FbSrSDjfScK/KwAvVTI5AS6r4VwbOMlIqtvRidnA=="
-    },
     "node-pre-gyp": {
       "version": "0.14.0",
       "resolved": "https://registry.npmjs.org/node-pre-gyp/-/node-pre-gyp-0.14.0.tgz",
diff --git a/package.json b/package.json
index d818cae..cbac758 100644
--- a/package.json
+++ b/package.json
@@ -15,7 +15,7 @@
     "license": "MIT",
     "dependencies": {
         "@hapi/joi": "^17.1.0",
-        "bcrypt": "^4.0.1",
+        "bcrypt": "^3.0.8",
         "body-parser": "^1.19.0",
         "dotenv": "^8.2.0",
         "express": "^4.17.1",
diff --git a/src/models/schema/attribute.js b/src/models/schema/attribute.js
index 8f285d2..6b37d3e 100644
--- a/src/models/schema/attribute.js
+++ b/src/models/schema/attribute.js
@@ -10,7 +10,16 @@ module.exports = (sequelize, DataTypes) => {
             primaryKey: true,
         },
         // This must be provided if editable is false
-        defaultValue: { type: DataTypes.TEXT },
+        defaultValue: {
+            type: DataTypes.TEXT,
+            validation: {
+                defaultValueValidation(editable) {
+                    if (editable === false && this.defaultValue !== null) throw new Error('defaultValue validation Error');
+                },
+            },
+
+
+        },
         editable: {
             type: DataTypes.BOOLEAN,
             defaultValue: false,
diff --git a/src/models/schema/item.js b/src/models/schema/item.js
index 0d0b3f3..8053f35 100644
--- a/src/models/schema/item.js
+++ b/src/models/schema/item.js
@@ -19,6 +19,11 @@ module.exports = (sequelize, DataTypes) => {
         labId: {
             type: DataTypes.UUID,
             references: { model: 'Lab', key: 'id' },
+            Validation: {
+                labIdValidation(isDraft) {
+                    if (isDraft === false && this.labId !== null) throw new Error('LabId validation failed');
+                },
+            },
         },
         itemSetId: {
             type: DataTypes.UUID,
diff --git a/src/models/schema/request.js b/src/models/schema/request.js
index ad24ac2..57ef16d 100644
--- a/src/models/schema/request.js
+++ b/src/models/schema/request.js
@@ -20,10 +20,40 @@ module.exports = (sequelize, DataTypes) => {
             references: { model: 'Supervisor', key: 'id' },
         },
         reason: { type: DataTypes.TEXT },
-        declineReason: { type: DataTypes.TEXT },
+        declineReason: {
+            type: DataTypes.TEXT,
+            Validation: {
+                declineReasonValidation(status) {
+                    const nNullList = ['DECLINED', 'INVALIDATED'];
+                    const nullList = ['REQUESTED', 'ACCEPTED'];
+
+                    nNullList.forEach((item) => {
+                        if (status.type === item && this.declineReason === null) throw new Error('Decline Reason Validation Error!');
+                    });
+
+                    nullList.forEach((item) => {
+                        if (status.type === item && this.returnedDate !== null) throw new Error('Decline Reason Validation Error!');
+                    });
+                },
+            },
+        },
         supervisorToken: {
             type: DataTypes.UUID,
             unique: 'supervisor_token',
+            Validation: {
+                supervisorTokenValidation(status) {
+                    const nNullList = ['REQUESTED', 'ACCEPTED'];
+                    const nullList = ['DECLINED', 'INVALIDATED'];
+
+                    nNullList.forEach((item) => {
+                        if (status.type === item && this.supervisorToken === null) throw new Error('Supervisor Token Validation Error!');
+                    });
+
+                    nullList.forEach((item) => {
+                        if (status.type === item && this.supervisorToken !== null) throw new Error('Supervisor Token Validation Error!');
+                    });
+                },
+            },
         },
         status: {
             type: DataTypes.ENUM('REQUESTED', 'ACCEPTED', 'DECLINED', 'INVALIDATED'),
diff --git a/src/models/schema/request_item.js b/src/models/schema/request_item.js
index 2dc0188..7dc10e7 100644
--- a/src/models/schema/request_item.js
+++ b/src/models/schema/request_item.js
@@ -10,9 +10,54 @@ module.exports = (sequelize, DataTypes) => {
             primaryKey: true,
             references: { model: 'Request', key: 'id' },
         },
-        returnedDate: { type: DataTypes.DATE },
-        dueDate: { type: DataTypes.DATE },
-        borrowedDate: { type: DataTypes.DATE },
+        returnedDate: {
+            type: DataTypes.DATE,
+            Validation: {
+                returnedDateValidation(status) {
+                    const nNullList = ['PENDING', 'BORROWED', 'REJECTED'];
+                    const nullList = ['RETURNED', 'EXPIRED'];
+                    nNullList.forEach((item) => {
+                        if (status.type === item && this.returnedDate !== null) throw new Error('Returned Date Validation Error!');
+                    });
+
+                    nullList.forEach((item) => {
+                        if (status.type === item && this.returnedDate === null) throw new Error('Returned Date Validation Error!');
+                    });
+                },
+            },
+        },
+        dueDate: {
+            type: DataTypes.DATE,
+            Validation: {
+                dueDateValidation(status) {
+                    const nNullList = ['PENDING', 'REJECTED'];
+                    const nullList = ['RETURNED', 'BORROWED', 'EXPIRED'];
+                    nNullList.forEach((item) => {
+                        if (status.type === item && this.dueDate !== null) throw new Error('Due Date Validation Error!');
+                    });
+
+                    nullList.forEach((item) => {
+                        if (status.type === item && this.dueDate === null) throw new Error('Due Date Validation Error!');
+                    });
+                },
+            },
+        },
+        borrowedDate: {
+            type: DataTypes.DATE,
+            Validation: {
+                borrowedDateValidation(status) {
+                    const nNullList = ['PENDING', 'REJECTED'];
+                    const nullList = ['RETURNED', 'BORROWED', 'EXPIRED'];
+                    nNullList.forEach((item) => {
+                        if (status.type === item && this.borrowedDate !== null) throw new Error('Borrowed Date Validation Error!');
+                    });
+
+                    nullList.forEach((item) => {
+                        if (status.type === item && this.borrowedDate === null) throw new Error('Borrowed Date Validation Error!');
+                    });
+                },
+            },
+        },
         status: {
             type: DataTypes.ENUM('PENDING', 'BORROWED', 'RETURNED', 'REJECTED', 'EXPIRED'),
             defaultValue: 'PENDING',