Example 1:  Suppose you buy a brand new washing machine for your home, but within a few weeks of using it, you encounter problems with it.  The machine doesn't start sometimes, or occasionally stops midway through washing, or the liquid soap oozes out of its door at times. If these issues happen frequently, would you consider the washing machine to a reliable product? 

Example 2: Suppose your car breaks down frequently and you have to get it towed to the garage every time to have it fixed.  Either the car has a manufacturing defect, has not been repaired properly earlier, or has developed a new problem.  Whatever may be the case, a car that breaks down frequently is not a reliable product. If the car breaks down, say, 3 times in 3 months, then it's MTBF is 90 days / 3 = 30 days.  If it takes a total of 6 hours to repair 3 breakdowns, then MTTR = 6 hours / 3 breakdowns = 2 hours.

Example 1: A mobile phone is considered a portable gadget as it can be carried around and used anywhere.  It owes its portability to its small size, light weight and battery power.  It also works on a wireless network. Contrast this with the refrigerator in your home that is large is size, quite heavy and requires AC mains power supply to operate, rendering it much less portable than a mobile phone.

Example 2: A wheel chair is considered a portable product as it has wheels, enabling it to be moved around easily compared to a regular chair that has no wheels.

Example 3:  A mobile number is considered portable if a customer can switch from one mobile service provider to another while continuing to use the same mobile number.  For e.g., when I switch my mobile service provider from Airtel to Vodafone, I can retain the same mobile number as before.  This is called mobile number portability.

Example 4: A furniture such as a big sofa that can be disassembled during transportation and re-assembled at the installation site can also be considered as portable.

Example 5: A software program that can be readily transferred from one computer (running operating system "A") to another computer (running operating system "B") is considered portable (for e.g., Java, Python, HTML, etc. programs) in contrast to those software programs that require modification before they can be run on computers with different operating systems.

• Modular design helps product designers handle complexity by breaking down the product's functionality into various less-complex modules or blocks, each with its own sub-functionality.

• By designing each block with well-defined interfaces, product designers can easily integrate various blocks with each other.   This gives rise to plug-n-play product architecture.

• Modular architecture makes repair and maintenance of the product easier.  A block that is faulty can be repaired or replaced with another block without impacting the rest of the product.

• Modular product blocks can be used independently or combined with different blocks to give rise to different product functionality or features.   This gives greater flexibility and convenience to users who would like to use different functionality of the product at different times and for different needs.

• By combining multiple 'similar' blocks together, it is possible to scale up / down the product capacity to handle increased / decreased load.

• If designed with the right intent, it is possible to integrate one or more third-party blocks with the product, thereby extending the functionality of the product.

Example:  Consider a home vacuum cleaner. Most of the modern vacuum cleaners come with multiple attachments such as brushes, hose pipes and nozzles. There are various types of brushes provided for cleaning floor, cleaning carpets, cleaning furniture, cleaning fabric, cleaning windows, etc. By attaching one hose pipe to another, one can extend the overall reach of the vacuum cleaner to clean ceiling, wall corners, floor corners, stairs, etc. using different sized nozzles.

Imagine for a moment if you had to buy different vacuum cleaners for each of the above jobs.  That would have been a nightmare !!  By making the vacuum cleaner design highly modular, it becomes possible for the user to buy one vacuum cleaner with multiple attachments, and use different attachments for different cleaning jobs. In case any of the attachments break, the user can just replace the particular attachment instead of buying an entirely new vacuum cleaner!

Example 1: Laptops and mobile phones provide users with the ability to connect to WiFi network of their choice by allowing users to configure the WiFi network's credentials (SSID and password) on it.  

Example 2: Car manufacturers design an engine and make many of its parameters configurable.  This makes it possible for them to tune the engine to meet the requirements of different markets without re-designing the engine for each market.  In addition, by allowing the engine parameters to be tunable, it becomes possible for service technicians to tune the performance, fuel-efficiency, or emission levels of the car to desired levels.

Example 3: Most modern smartphones allow users to configure a WiFi hotspot on the fly, making it possible for other devices to connect to the hotspot using the hotspot's credentials (SSID, password and security type).

Without the ability to configure, a product would remain set to factory default settings and would not be usable in different user environments or operate at the desired performance levels.

Example 1: Today's smartphones have several apps installed on them.  These apps need to be updated from time-to-time to take advantage of the latest features made available by its developers. Smartphones allow you to either "auto-update" the apps or "manually update" the apps.  If you choose the auto-update option, your apps get automatically updated on your phone as and when new updates are available for the apps on the App Store. This is an example of a self-managed product. Alternatively, you can disable the auto-update option and choose to update your apps selectively by yourself.  This is an example of manually managed product. 

Example 2: Alexa app can be used to locally setup and manage Amazon's Echo voice assistant device in your home.  This is an example of local manageability where both the mobile phone running Alexa app and the Echo device are connected to the same WiFi network. 

Example 3: A remote computer can be used to remotely login to the computer network in your school or office in order to install software tools, configure network settings, setup anti-virus software and user accounts, etc.  This is an example of remote manageability. 

Example 4: A laser printer can be managed locally by its user for loading paper, configuring print settings, etc., or remotely managed or metered by an external system over the network.

Example 1:  Take the case of a luggage-carrier that can be fitted on top of a car.  This is an extension that can be added to the car to enhance its ability to carry luggage on its roof.

Example 2: Railway coaches are designed and built keeping extensibility in mind.  A train's capacity to carry additional people or goods can be dynamically extended by adding additional coaches using inter-coach coupling mechanisms.

Example 3: Moto Mods are extensions that can be attached to Motorola smartphones to extend the functionality of the phone.  The extension Mods include zoom lens,  speaker, power bank, projector, wireless charger, vehicle mount, etc.  These Mods can be snapped onto the phone using magnetic contacts. 

Example 4: Consider a sofa with built-in extension that allows it to be converted into a bed.  During day time, the extension is folded-in, allowing users to sit on the sofa.  At night times, the bed extension can be pulled out allowing users to sleep on it.

Example 1:  Haven't you noticed manholes on street corners?  They are used to carry out inspection, cleaning and removing obstruction in the sewer line.  Manholes have a removable lid that can be opened by municipal staff for maintenance operations.  Without a manhole designed as part of the sewer network, it would be very difficult to carry out maintenance operations.

Example 2: Modern cars have a connector called "OBD Port" in them. It is usually found underneath the car's dashboard or below the glove compartment.  The OBD port facilitates maintenance activities by service engineers.  Service engineers connect a computer to the OBD port through a cable in order to diagnose the car's emission levels, mileage, speed and tune the car's engine performance.   Without the OBD port, it would be difficult to diagnose or tune the engine.  The OBD port makes the maintenance job easier.

Example 3: Today, most computer manufacturers offer remote assistance service to buyers of laptops or desktop computers.  In case you have any trouble with your computer, you can call the service center, and a service engineer will remotely login to your computer and fix it. This is an example of remote maintenance.  If your computer didn't have remote access capability built-in, you would have to physically carry your computer to the service center to have it fixed.

Example 1:  What if you need to transport 40 people from point A to point B.  Either you use of a big bus which can accommodate 40 people (vertical scaling), or press into service several buses or cars to do the same job (horizontal scaling).  Either way, you can handle the increase in load (people to be transported) by scaling up vertically or horizontally.

Example 2: Suppose you have a software application running on a computer and there is a spurt in the number of users using your software application.  How do you handle the increased load on your software?  You can either put in place a bigger computer (with greater processing power, memory and storage) to run your software application (vertical scaling), or add several small computers that run in parallel to share the increase in load.

Example 3: An extensible dining table can be scaled up / down to seat more / less people around it.

Example 4: A train can be scaled out (horizontally) to carry more passengers by adding several coaches to it, or scaled up (vertically) to carry more passengers by having a small number of double-decker coaches, that each carry more people.