Nested Objects - Design Question

Hello together,

(this is my first post) :-)

I have a database design question for laravel eloquent.

Right now I'm trying to make a nested database structure to detect times (f.e. 15 Mintues) for different services.

An example. I have the following tables:

ServiceType (id,name): Category 1, Category 2, Category 3

ServiceCategories (id,name,service_type_id): Repair (Category 1), Solder (Category 1), Disassemble (Category 2), Destroy (Category 3)

Services: (id, name, default_workload, service_category_id): Solder 1 (Solder): 15Min, Solder 2 (Solder) 30 Min, Solder 3 (Solder) 10 Min, Repair 1 (Repair) 10Min, Repair 2 (Repair) 20Min, Disassemble 1 (Disassemble) 40 Min, Destroy 1 (Destroy) 10 Min

So this structure works for now, the database looks like:

Services:

    Schema::create('services', function (Blueprint $table) {
        $table->bigIncrements('id');
        $table->integer('service_category_id')->unsigned()->index();
        $table->string('name');
        $table->time('default_workload');
        $table->timestamps();
        $table->foreign('service_category_id')->references('id')->on('service_categories')->onDelete('cascade');
    });

ServiceCategories:

    Schema::create('service_categories', function (Blueprint $table) {
        $table->increments('id');
        $table->integer('service_type_id')->unsigned()->index();
        $table->string('name');
        $table->timestamps();
        $table->foreign('service_type_id')->references('id')->on('service_types')->onDelete('cascade');
    });

ServiceTypes:

    Schema::create('service_types', function (Blueprint $table) {
        $table->increments('id');
        $table->string('name');
        $table->timestamps();
    });

Now I want to add the option to choose for another category. This is where my question starts. At all, the structure for my database should look like:

Category 1 -> Category 2 -> ServiceCategory - Service

The Category 2 could have following content:

Short, Middle, Long

As I choose short, middle, long .. the default_workload for the service changes. (f.e. + 15 Minute), additional minutes will be added to the default_workload.

Now I thought about different options to solve this problem:

• Put a table in between category 1 and service category. in this case i would multiply all my service categorys 3 times. Because I would need them for each Category 2 (short, middle, long). Which would not be optimal, because the ServiceCategories stay the same for a Category all the time. It does not depent on Category 2
• Link the Category 2 to a Service. This would be a good solution (so i thought). But after "almost" implementing this I realized it could be complicated in selecting a default_workload. In this case I would have to look for a default_workload or "if there is" a link to Category 2 a value from Category 2.

Right now I think I made a design failure and try to work around it. Maybe somebody can help me out?

Some ideas, experience on this?

Thank you so much!