diff --git a/migrations/Version20260312171810.php b/migrations/Version20260312171810.php
new file mode 100644
index 0000000..b1b0a0c
--- /dev/null
+++ b/migrations/Version20260312171810.php
@@ -0,0 +1,47 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+final class Version20260312171810 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'Create piece_products join table and migrate data from Piece.productIds JSON column';
+    }
+
+    public function up(Schema $schema): void
+    {
+        $this->addSql('CREATE TABLE IF NOT EXISTS piece_products (piece_id VARCHAR(36) NOT NULL, product_id VARCHAR(36) NOT NULL, PRIMARY KEY (piece_id, product_id))');
+        $this->addSql('CREATE INDEX IF NOT EXISTS IDX_87C835B5C40FCFA8 ON piece_products (piece_id)');
+        $this->addSql('CREATE INDEX IF NOT EXISTS IDX_87C835B54584665A ON piece_products (product_id)');
+        $this->addSql('ALTER TABLE piece_products DROP CONSTRAINT IF EXISTS FK_87C835B5C40FCFA8');
+        $this->addSql('ALTER TABLE piece_products ADD CONSTRAINT FK_87C835B5C40FCFA8 FOREIGN KEY (piece_id) REFERENCES pieces (id) ON DELETE CASCADE NOT DEFERRABLE');
+        $this->addSql('ALTER TABLE piece_products DROP CONSTRAINT IF EXISTS FK_87C835B54584665A');
+        $this->addSql('ALTER TABLE piece_products ADD CONSTRAINT FK_87C835B54584665A FOREIGN KEY (product_id) REFERENCES products (id) ON DELETE CASCADE NOT DEFERRABLE');
+
+        // Migrate Piece.productIds JSON array → piece_products join table
+        $this->addSql(<<<'SQL'
+            INSERT INTO piece_products (piece_id, product_id)
+            SELECT DISTINCT p.id, pid.value
+            FROM pieces p,
+            LATERAL jsonb_array_elements_text(p.productids::jsonb) AS pid(value)
+            WHERE p.productids IS NOT NULL
+              AND p.productids::jsonb != '[]'::jsonb
+              AND jsonb_array_length(p.productids::jsonb) > 0
+              AND EXISTS (SELECT 1 FROM products pr WHERE pr.id = pid.value)
+              AND NOT EXISTS (SELECT 1 FROM piece_products pp WHERE pp.piece_id = p.id AND pp.product_id = pid.value)
+            SQL);
+    }
+
+    public function down(Schema $schema): void
+    {
+        $this->addSql('ALTER TABLE piece_products DROP CONSTRAINT IF EXISTS FK_87C835B5C40FCFA8');
+        $this->addSql('ALTER TABLE piece_products DROP CONSTRAINT IF EXISTS FK_87C835B54584665A');
+        $this->addSql('DROP TABLE IF EXISTS piece_products');
+    }
+}
diff --git a/migrations/Version20260312190000.php b/migrations/Version20260312190000.php
new file mode 100644
index 0000000..56c2297
--- /dev/null
+++ b/migrations/Version20260312190000.php
@@ -0,0 +1,248 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+/**
+ * Create composant slot tables and migrate existing JSON data from composant.structure.
+ */
+final class Version20260312190000 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'Create composant_piece_slots, composant_subcomponent_slots, composant_product_slots tables and migrate data from composant.structure JSON';
+    }
+
+    public function up(Schema $schema): void
+    {
+        // ── Table creation (idempotent) ──────────────────────────────────────
+
+        $this->addSql(<<<'SQL'
+                CREATE TABLE IF NOT EXISTS composant_piece_slots (
+                    id VARCHAR(36) NOT NULL,
+                    "composantid" VARCHAR(36) NOT NULL,
+                    "typepieceid" VARCHAR(36) DEFAULT NULL,
+                    "selectedpieceid" VARCHAR(36) DEFAULT NULL,
+                    quantity INT NOT NULL DEFAULT 1,
+                    position INT NOT NULL DEFAULT 0,
+                    "createdat" TIMESTAMP(0) WITHOUT TIME ZONE NOT NULL,
+                    "updatedat" TIMESTAMP(0) WITHOUT TIME ZONE NOT NULL,
+                    PRIMARY KEY (id)
+                )
+            SQL);
+
+        $this->addSql(<<<'SQL'
+                CREATE TABLE IF NOT EXISTS composant_subcomponent_slots (
+                    id VARCHAR(36) NOT NULL,
+                    "composantid" VARCHAR(36) NOT NULL,
+                    alias VARCHAR(255) DEFAULT NULL,
+                    "familycode" VARCHAR(255) DEFAULT NULL,
+                    "typecomposantid" VARCHAR(36) DEFAULT NULL,
+                    "selectedcomposantid" VARCHAR(36) DEFAULT NULL,
+                    position INT NOT NULL DEFAULT 0,
+                    "createdat" TIMESTAMP(0) WITHOUT TIME ZONE NOT NULL,
+                    "updatedat" TIMESTAMP(0) WITHOUT TIME ZONE NOT NULL,
+                    PRIMARY KEY (id)
+                )
+            SQL);
+
+        $this->addSql(<<<'SQL'
+                CREATE TABLE IF NOT EXISTS composant_product_slots (
+                    id VARCHAR(36) NOT NULL,
+                    "composantid" VARCHAR(36) NOT NULL,
+                    "typeproductid" VARCHAR(36) DEFAULT NULL,
+                    "selectedproductid" VARCHAR(36) DEFAULT NULL,
+                    "familycode" VARCHAR(255) DEFAULT NULL,
+                    position INT NOT NULL DEFAULT 0,
+                    "createdat" TIMESTAMP(0) WITHOUT TIME ZONE NOT NULL,
+                    "updatedat" TIMESTAMP(0) WITHOUT TIME ZONE NOT NULL,
+                    PRIMARY KEY (id)
+                )
+            SQL);
+
+        // ── Indexes (idempotent) ─────────────────────────────────────────────
+
+        $this->addSql('CREATE INDEX IF NOT EXISTS idx_comp_piece_slot_composant ON composant_piece_slots("composantid")');
+        $this->addSql('CREATE INDEX IF NOT EXISTS idx_comp_piece_slot_piece ON composant_piece_slots("selectedpieceid")');
+        $this->addSql('CREATE INDEX IF NOT EXISTS idx_comp_piece_slot_type ON composant_piece_slots("typepieceid")');
+        $this->addSql('CREATE INDEX IF NOT EXISTS idx_comp_sub_slot_composant ON composant_subcomponent_slots("composantid")');
+        $this->addSql('CREATE INDEX IF NOT EXISTS idx_comp_sub_slot_typecomp ON composant_subcomponent_slots("typecomposantid")');
+        $this->addSql('CREATE INDEX IF NOT EXISTS idx_comp_sub_slot_selected ON composant_subcomponent_slots("selectedcomposantid")');
+        $this->addSql('CREATE INDEX IF NOT EXISTS idx_comp_prod_slot_composant ON composant_product_slots("composantid")');
+        $this->addSql('CREATE INDEX IF NOT EXISTS idx_comp_prod_slot_type ON composant_product_slots("typeproductid")');
+        $this->addSql('CREATE INDEX IF NOT EXISTS idx_comp_prod_slot_selected ON composant_product_slots("selectedproductid")');
+
+        // ── Foreign keys (idempotent via DO $$ block) ────────────────────────
+
+        // composant_piece_slots FKs
+        $this->addSql(<<<'SQL'
+                DO $$ BEGIN
+                    IF NOT EXISTS (SELECT 1 FROM pg_constraint WHERE conname = 'fk_comp_piece_slot_composant') THEN
+                        ALTER TABLE composant_piece_slots
+                            ADD CONSTRAINT fk_comp_piece_slot_composant
+                            FOREIGN KEY ("composantid") REFERENCES composants (id) ON DELETE CASCADE;
+                    END IF;
+                END $$
+            SQL);
+
+        $this->addSql(<<<'SQL'
+                DO $$ BEGIN
+                    IF NOT EXISTS (SELECT 1 FROM pg_constraint WHERE conname = 'fk_comp_piece_slot_type') THEN
+                        ALTER TABLE composant_piece_slots
+                            ADD CONSTRAINT fk_comp_piece_slot_type
+                            FOREIGN KEY ("typepieceid") REFERENCES model_types (id) ON DELETE SET NULL;
+                    END IF;
+                END $$
+            SQL);
+
+        $this->addSql(<<<'SQL'
+                DO $$ BEGIN
+                    IF NOT EXISTS (SELECT 1 FROM pg_constraint WHERE conname = 'fk_comp_piece_slot_piece') THEN
+                        ALTER TABLE composant_piece_slots
+                            ADD CONSTRAINT fk_comp_piece_slot_piece
+                            FOREIGN KEY ("selectedpieceid") REFERENCES pieces (id) ON DELETE SET NULL;
+                    END IF;
+                END $$
+            SQL);
+
+        // composant_subcomponent_slots FKs
+        $this->addSql(<<<'SQL'
+                DO $$ BEGIN
+                    IF NOT EXISTS (SELECT 1 FROM pg_constraint WHERE conname = 'fk_comp_sub_slot_composant') THEN
+                        ALTER TABLE composant_subcomponent_slots
+                            ADD CONSTRAINT fk_comp_sub_slot_composant
+                            FOREIGN KEY ("composantid") REFERENCES composants (id) ON DELETE CASCADE;
+                    END IF;
+                END $$
+            SQL);
+
+        $this->addSql(<<<'SQL'
+                DO $$ BEGIN
+                    IF NOT EXISTS (SELECT 1 FROM pg_constraint WHERE conname = 'fk_comp_sub_slot_typecomp') THEN
+                        ALTER TABLE composant_subcomponent_slots
+                            ADD CONSTRAINT fk_comp_sub_slot_typecomp
+                            FOREIGN KEY ("typecomposantid") REFERENCES model_types (id) ON DELETE SET NULL;
+                    END IF;
+                END $$
+            SQL);
+
+        $this->addSql(<<<'SQL'
+                DO $$ BEGIN
+                    IF NOT EXISTS (SELECT 1 FROM pg_constraint WHERE conname = 'fk_comp_sub_slot_selected') THEN
+                        ALTER TABLE composant_subcomponent_slots
+                            ADD CONSTRAINT fk_comp_sub_slot_selected
+                            FOREIGN KEY ("selectedcomposantid") REFERENCES composants (id) ON DELETE SET NULL;
+                    END IF;
+                END $$
+            SQL);
+
+        // composant_product_slots FKs
+        $this->addSql(<<<'SQL'
+                DO $$ BEGIN
+                    IF NOT EXISTS (SELECT 1 FROM pg_constraint WHERE conname = 'fk_comp_prod_slot_composant') THEN
+                        ALTER TABLE composant_product_slots
+                            ADD CONSTRAINT fk_comp_prod_slot_composant
+                            FOREIGN KEY ("composantid") REFERENCES composants (id) ON DELETE CASCADE;
+                    END IF;
+                END $$
+            SQL);
+
+        $this->addSql(<<<'SQL'
+                DO $$ BEGIN
+                    IF NOT EXISTS (SELECT 1 FROM pg_constraint WHERE conname = 'fk_comp_prod_slot_type') THEN
+                        ALTER TABLE composant_product_slots
+                            ADD CONSTRAINT fk_comp_prod_slot_type
+                            FOREIGN KEY ("typeproductid") REFERENCES model_types (id) ON DELETE SET NULL;
+                    END IF;
+                END $$
+            SQL);
+
+        $this->addSql(<<<'SQL'
+                DO $$ BEGIN
+                    IF NOT EXISTS (SELECT 1 FROM pg_constraint WHERE conname = 'fk_comp_prod_slot_selected') THEN
+                        ALTER TABLE composant_product_slots
+                            ADD CONSTRAINT fk_comp_prod_slot_selected
+                            FOREIGN KEY ("selectedproductid") REFERENCES products (id) ON DELETE SET NULL;
+                    END IF;
+                END $$
+            SQL);
+
+        // ── Data migration: composant.structure.pieces → composant_piece_slots ──
+
+        $this->addSql(<<<'SQL'
+                INSERT INTO composant_piece_slots (id, "composantid", "typepieceid", "selectedpieceid", quantity, position, "createdat", "updatedat")
+                SELECT
+                    'cl' || encode(gen_random_bytes(12), 'hex'),
+                    c.id,
+                    NULLIF(piece->'definition'->>'typePieceId', ''),
+                    NULLIF(piece->>'selectedPieceId', ''),
+                    1,
+                    (ordinality - 1)::int,
+                    NOW(), NOW()
+                FROM composants c,
+                LATERAL jsonb_array_elements(c.structure::jsonb->'pieces') WITH ORDINALITY AS t(piece, ordinality)
+                WHERE c.structure IS NOT NULL
+                  AND (c.structure::jsonb->'pieces') IS NOT NULL
+                  AND jsonb_array_length(c.structure::jsonb->'pieces') > 0
+                  AND NOT EXISTS (SELECT 1 FROM composant_piece_slots cps WHERE cps."composantid" = c.id)
+                  AND (NULLIF(piece->'definition'->>'typePieceId', '') IS NULL OR EXISTS (SELECT 1 FROM model_types mt WHERE mt.id = piece->'definition'->>'typePieceId'))
+                  AND (NULLIF(piece->>'selectedPieceId', '') IS NULL OR EXISTS (SELECT 1 FROM pieces p WHERE p.id = piece->>'selectedPieceId'))
+            SQL);
+
+        // ── Data migration: composant.structure.subcomponents → composant_subcomponent_slots ──
+
+        $this->addSql(<<<'SQL'
+                INSERT INTO composant_subcomponent_slots (id, "composantid", alias, "familycode", "typecomposantid", "selectedcomposantid", position, "createdat", "updatedat")
+                SELECT
+                    'cl' || encode(gen_random_bytes(12), 'hex'),
+                    c.id,
+                    COALESCE(sub->'definition'->>'alias', ''),
+                    COALESCE(sub->'definition'->>'familyCode', ''),
+                    NULLIF(sub->'definition'->>'typeComposantId', ''),
+                    NULLIF(sub->>'selectedComponentId', ''),
+                    (ordinality - 1)::int,
+                    NOW(), NOW()
+                FROM composants c,
+                LATERAL jsonb_array_elements(c.structure::jsonb->'subcomponents') WITH ORDINALITY AS t(sub, ordinality)
+                WHERE c.structure IS NOT NULL
+                  AND (c.structure::jsonb->'subcomponents') IS NOT NULL
+                  AND jsonb_array_length(c.structure::jsonb->'subcomponents') > 0
+                  AND NOT EXISTS (SELECT 1 FROM composant_subcomponent_slots css WHERE css."composantid" = c.id)
+                  AND (NULLIF(sub->'definition'->>'typeComposantId', '') IS NULL OR EXISTS (SELECT 1 FROM model_types mt WHERE mt.id = sub->'definition'->>'typeComposantId'))
+                  AND (NULLIF(sub->>'selectedComponentId', '') IS NULL OR EXISTS (SELECT 1 FROM composants sc WHERE sc.id = sub->>'selectedComponentId'))
+            SQL);
+
+        // ── Data migration: composant.structure.products → composant_product_slots ──
+
+        $this->addSql(<<<'SQL'
+                INSERT INTO composant_product_slots (id, "composantid", "typeproductid", "selectedproductid", "familycode", position, "createdat", "updatedat")
+                SELECT
+                    'cl' || encode(gen_random_bytes(12), 'hex'),
+                    c.id,
+                    NULLIF(prod->'definition'->>'typeProductId', ''),
+                    NULLIF(prod->>'selectedProductId', ''),
+                    prod->'definition'->>'familyCode',
+                    (ordinality - 1)::int,
+                    NOW(), NOW()
+                FROM composants c,
+                LATERAL jsonb_array_elements(c.structure::jsonb->'products') WITH ORDINALITY AS t(prod, ordinality)
+                WHERE c.structure IS NOT NULL
+                  AND (c.structure::jsonb->'products') IS NOT NULL
+                  AND jsonb_array_length(c.structure::jsonb->'products') > 0
+                  AND NOT EXISTS (SELECT 1 FROM composant_product_slots cps WHERE cps."composantid" = c.id)
+                  AND (NULLIF(prod->'definition'->>'typeProductId', '') IS NULL OR EXISTS (SELECT 1 FROM model_types mt WHERE mt.id = prod->'definition'->>'typeProductId'))
+                  AND (NULLIF(prod->>'selectedProductId', '') IS NULL OR EXISTS (SELECT 1 FROM products p WHERE p.id = prod->>'selectedProductId'))
+            SQL);
+    }
+
+    public function down(Schema $schema): void
+    {
+        $this->addSql('DROP TABLE IF EXISTS composant_product_slots');
+        $this->addSql('DROP TABLE IF EXISTS composant_subcomponent_slots');
+        $this->addSql('DROP TABLE IF EXISTS composant_piece_slots');
+    }
+}
diff --git a/src/Entity/Piece.php b/src/Entity/Piece.php
index e8ca2dd..d73017d 100644
--- a/src/Entity/Piece.php
+++ b/src/Entity/Piece.php
@@ -109,6 +109,15 @@ class Piece
     #[Groups(['piece:read'])]
     private Collection $customFieldValues;
 
+    /**
+     * @var Collection<int, Product>
+     */
+    #[ORM\ManyToMany(targetEntity: Product::class, inversedBy: 'linkedPieces')]
+    #[ORM\JoinTable(name: 'piece_products')]
+    #[ORM\JoinColumn(name: 'piece_id', referencedColumnName: 'id', onDelete: 'CASCADE')]
+    #[ORM\InverseJoinColumn(name: 'product_id', referencedColumnName: 'id', onDelete: 'CASCADE')]
+    private Collection $products;
+
     /**
      * @var Collection<int, MachinePieceLink>
      */
@@ -130,6 +139,7 @@ class Piece
         $this->constructeurs     = new ArrayCollection();
         $this->documents         = new ArrayCollection();
         $this->customFieldValues = new ArrayCollection();
+        $this->products          = new ArrayCollection();
         $this->machineLinks      = new ArrayCollection();
     }
 
@@ -298,4 +308,28 @@ class Piece
     {
         return $this->customFieldValues;
     }
+
+    /**
+     * @return Collection<int, Product>
+     */
+    public function getProducts(): Collection
+    {
+        return $this->products;
+    }
+
+    public function addProduct(Product $product): static
+    {
+        if (!$this->products->contains($product)) {
+            $this->products->add($product);
+        }
+
+        return $this;
+    }
+
+    public function removeProduct(Product $product): static
+    {
+        $this->products->removeElement($product);
+
+        return $this;
+    }
 }
diff --git a/src/Entity/Product.php b/src/Entity/Product.php
index 5e0acc9..0699548 100644
--- a/src/Entity/Product.php
+++ b/src/Entity/Product.php
@@ -106,6 +106,12 @@ class Product
     #[ORM\OneToMany(mappedBy: 'product', targetEntity: Composant::class)]
     private Collection $composants;
 
+    /**
+     * @var Collection<int, Piece>
+     */
+    #[ORM\ManyToMany(targetEntity: Piece::class, mappedBy: 'products')]
+    private Collection $linkedPieces;
+
     /**
      * @var Collection<int, MachineProductLink>
      */
@@ -129,6 +135,7 @@ class Product
         $this->customFieldValues = new ArrayCollection();
         $this->pieces            = new ArrayCollection();
         $this->composants        = new ArrayCollection();
+        $this->linkedPieces      = new ArrayCollection();
         $this->machineLinks      = new ArrayCollection();
     }
 
@@ -219,4 +226,12 @@ class Product
     {
         return $this->customFieldValues;
     }
+
+    /**
+     * @return Collection<int, Piece>
+     */
+    public function getLinkedPieces(): Collection
+    {
+        return $this->linkedPieces;
+    }
 }