https://runkit.com/sachinsmc/using-event-emitter

task4.js

const { EventEmitter } = require('events');

var input = {
    "orders": [
        [
            "Pepperoni",
            "Mushrooms",
            "Sausage"
        ]
    ]
};


/**
 * Restaurant class is reponsible for processing orders, it extends eventEmitter
 */
class Restaurant extends EventEmitter {

    constructor(doughChefs, toppingChefs, isOvenFree, waiters, orders, report) {
        super();
        this.doughChefs = doughChefs;
        this.toppingChefs = toppingChefs;
        this.isOvenFree = isOvenFree;
        this.waiters = waiters;
        this.orders = orders;
        this.servedOrders = 0;
        this.report = "\n========= Report ========= \n";
        this.orderReport = "\n========= Report for each order ========= \n";
        this.orderTimings = {};
        this.currentOrder = 0;
        this.completed = 0;
    }

    /**
     * This methods handles order dough
     * @param {Order} order 
     */
    dough(order) {
        console.log('dough: ' + order + new Date());
        this.currentOrder++
        this.orderTimings[`${this.currentOrder}`] = ["Started At : " + new Date()]
        setTimeout(() => {
            this.noOfToppings = order.length
            this.doughChefs++
            this.emit('topping', order);
        }, 7000)
    }

    /**
     * This methods handles order topping
     * @param {Order} order 
     */
    topping(order) {
        console.log('topping: ' + order + new Date());
        setTimeout(() => {
            if (this.noOfToppings <= 0 || this.noOfToppings < 6) {
                this.emit('oven', order);
            } else {
                this.noOfToppings -= 6
                this.emit('topping', order);
            }
        }, 4000);
    }

    /**
     * This methods handles order oven
     * @param {Order} order 
     */
    oven(order) {
        if (this.isOvenFree) {
            this.isOvenFree = false;
            console.log('oven: ' + order + new Date());
            setTimeout(() => {
                this.emit('serve', order);
            }, 10000);
        } else {
            setTimeout(() => {
                this.emit('oven', order);
            }, 10000);
        }
    }

    /**
     * This methods handles order serving
     * @param {Order} order 
     */
    serve(order) {
        this.isOvenFree = true;
        if (this.Waiters > 0) {
            this.Waiters--
            setTimeout(() => {
                this.Waiters++
                this.servedOrders++
                console.log('served: ' + order + new Date());
            }, 5000);
        } else {
            this.Waiters--
            setTimeout(() => {
                console.log('served: ' + order + new Date())
                this.servedOrders++
                this.areThereMoreOrders(this.currentOrder)
            }, 5000);
        }

    }

    areThereMoreOrders() {
        this.completed++
        this.orderTimings[`${this.completed}`].push("Completed At : " + new Date())
        this.orderTimings[`${this.completed}`].push('Took more than 26s')

        this.Waiters++
        if (this.orders.length === this.servedOrders) {
            this.report += `\nServed all ${this.servedOrders} orders at : ${new Date()}`
            console.log(this.report)
            console.timeEnd("Order processing took ")
            console.log("\n \n")
            console.log(this.orderReport)
            console.log(this.orderTimings)
        }
        return
    }



    /**
     * This is starting point, it will process order
     */
    processOrder() {
        console.time("Order processing took ")
        console.log(`\nStarting Processing ${this.orders.length} orders\n`)
        this.report += `\nStarted ${this.orders.length} orders processing at : ${new Date()}`
        for (let i = 0; i < this.orders.length; i++) {
            if (this.doughChefs > 0) {
                this.emit('dough', input.orders[i]);
                this.doughChefs--
            } else {
                setTimeout(() => {
                    this.emit('dough', input.orders[i]);
                    this.doughChefs--
                }, 7000)
            }
        }
    }
}

const restaurant = new Restaurant(2, 3, true, 2, input.orders);

restaurant.on('dough', restaurant.dough);
restaurant.on('topping', restaurant.topping);
restaurant.on('oven', restaurant.oven);
restaurant.on('serve', restaurant.serve);

// Process order
restaurant.processOrder()

========= Report =========

Started 1 orders processing at : Thu Oct 28 2021 23:50:13 GMT+0400 (Gulf Standard Time)
Served all 1 orders at : Thu Oct 28 2021 23:50:39 GMT+0400 (Gulf Standard Time)
Order processing took : 26.026s




========= Report for each order =========

{
  '1': [
    'Started At : Thu Oct 28 2021 23:50:13 GMT+0400 (Gulf Standard Time)',
    'Completed At : Thu Oct 28 2021 23:50:39 GMT+0400 (Gulf Standard Time)',
    'Took more than 26s'
  ]
}

@Amzul Your thoughts on this?