How do you write specifications for the project

Thread Starter

Pushkar1

Joined Apr 5, 2021
416
When we think of designing a project, the first thing that is written is the specification.

For example, if a pocket size personal computer is to be designed, how can the specifications be written?

Will the specifications be what parts like CPU, memory keyboard, Wi-Fi chip, bluetooth, camera, speaker will be there for this.

Will it be in the specification that what can a personal computer do like This can take photos, play songs, play videos, run Browser, save personal information .. etc

What do you think the specification should be for a pocket size PC? If you had to write a specification which specification would you write?
 
Last edited:

KeithWalker

Joined Jul 10, 2017
2,100
There are different criteria for specifications, depending on the device and who will be reading it.
There is a "Functional Specification" which will describe in detail what the device will do. That is usually prepared for budgeting and management who do not have in-depth technical knowledge.
There is the "Technical Specification" which contains the parameters and limits of the various functions of the device.
Usually, neither one will will list the specific parts used in the device. Those are included in the "Manufacturing Specification".
 

ericgibbs

Joined Jan 29, 2010
14,729
For example, if a pocket size personal computer is to be designed, how can the specifications be written?
Hi P,
The specification is mainly determined by the build/selling price and the perceived end user.

E
 

Thread Starter

Pushkar1

Joined Apr 5, 2021
416
Hi P,
The specification is mainly determined by the build/selling price and the perceived end user.
Maybe you're pointing to another direction.

I have seen in many discussions that they say specification is needed before designing the system. it is said that before designing the system, we need the specifications that tell what the system supposed to do.
 

ericgibbs

Joined Jan 29, 2010
14,729
hi P,
You cannot create a draft technical specification for any product, unless you have a budget costing and a market for the product.

This is usually done by the Marketing/Sales Dept, they draw up a concept specification.

Put your Marketing hat on, create a product proposal.

E
 

KeithWalker

Joined Jul 10, 2017
2,100
For a new product to be developed, there are a number of different stages it has to go through. The first is the concept, where product is born. This is just an idea. A requirements list is created which is then broken down into must-have and would-like features.
Using this document, a feasibility study is performed to find the simplest and most cost effective ways of creating the different features and how the features can be tested. The results are used to prepare a cost sheet. This is when the budgeting entity has to decide which features to retain.
After that, the different specifications can be drawn up.
The actual production has to go through a number of development stages before it can become the final product.
These will include prototypes and Alpha and Beta test units.

I hope this gives you a little more insight into how products are conceived and how the various specifications are created.
 

Thread Starter

Pushkar1

Joined Apr 5, 2021
416
I am giving a description of a system below, I want to know what is this whole process called

  1. System supposed to run browser
  2. System supposed to display picture
  3. System supposed to play music
  4. System supposed to show videos
  5. System supposed to save record
  6. System supposed to connect USB device
  7. System supposed to connect HDMI device
  8. System supposed to connect IP camera

I am interested to know what this description is called in technical language. Is it called a problem statement or a specification or a requirement or something else?
 

MrChips

Joined Oct 2, 2009
25,066
Eric is right.

The first place to start is write the User Manual. This will describe how the user is expected to use the product.
Then you need a photograph of the product so that people know what you are talking about. This is where you need to create a mockup of the product.

Marketing needs this mockup and photographs so that they can conduct a market survey, project potential sales volume and target price.

The bottom line is, do the marketing first before anything else.
 

Thread Starter

Pushkar1

Joined Apr 5, 2021
416
Eric is right.
Do the following points come under the category of requirement? or Is it a technical specification? or is it called something else?

1) Decide which processor is needed for the system

2) Decide what resolution is required for display in the system

3) Decide How many megapixel cameras are needed in the system
 

ericgibbs

Joined Jan 29, 2010
14,729
Hi P,
Consider in post #12.
Item #1, choose an off the shelf CPU specification that just exceeds the claimed specification of your products' data sheet.

item #2 as item #1
item #3, as item #1

Remember, the cost of the final product must meet the Marketing/Sales manufacturing/ selling price.

Business is about making a Profit, not just paying Bills.

E

OT:
My signature message is from many years of experience in this field in running my own companies.
 

Thread Starter

Pushkar1

Joined Apr 5, 2021
416
Hi P,
Consider in post #12.
Item #1, choose an off the shelf CPU specification that just exceeds the claimed specification of your products' data sheet.
I tried very hard to understand what are the requirements and specifications for a product and some points are shown in the example. So I understood that the requirement is to give a detailed description, what product supposed to do? But practically I do not understand what should be the specification example.

Do you have an example of a product that clearly describes the requirements and specification of the product?
 

ericgibbs

Joined Jan 29, 2010
14,729
hi P,
I will put some thought into how best I can answer your question.
Do you have an example of a product that clearly describes the requirements and specification of the product?

The requirement is usually determined by the buyer of the product and the specification by the seller of the product

You should also consider some companies, as we have said, do a market survey and carry out an 'in house' development of a product that meets the requirement of the market survey and sells the product through their own agents.

Other times, a potential buyer asks you to develop/design a product to their specification for them to build and sell.

E

I will try to expand on this reply.:)
 

KeithWalker

Joined Jul 10, 2017
2,100
I tried very hard to understand what are the requirements and specifications for a product and some points are shown in the example. So I understood that the requirement is to give a detailed description, what product supposed to do? But practically I do not understand what should be the specification example.

Do you have an example of a product that clearly describes the requirements and specification of the product?
Look in the operator manual of any high quality measuring instrument from a reputable company, e.g. Tektronix, Keysight, B&K, etc.. The introduction will outline the functional specification which is a description of what the device will do.. Then there will be detailed instructions on how to use the device. There will be a complete technical specification for reference. This is used to calculate the accuracy of the different parameters as measured by the instrument and the maximum permissable inputs. It's usually towards the end of the manual in the appendix.
 
Last edited:

ericgibbs

Joined Jan 29, 2010
14,729
Hi P,
Let’s try this way of understanding the procedure, for a Client contacting you.

I come to you and ask that you quote for designing this ‘imaginary’ product and create a working prototype.

" My idea is to design and manufacture a product that will measure the Temperature and Humidity of my Green house, which is, located, approx. 50mtrs from my home.

The Green house unit will measure these parameters every minute and transmit by a radio link, using RS232 protocols, to a receiver in my house. The receiver will display and log the parameters to a SD card.

If successful, I think I can sell up to 100 units per annum, and I am looking for a selling price of less than £25GBP."


P,
Post what you consider, what is the next step?

E
 

Yaakov

Joined Jan 27, 2019
4,074
As an aside, no product is developed in a vacuum. Even "new inventions" are rarely revolutionary, they are rather evolutionary.

If you are trying to solve a problem, which is what a successful product does, you will have other examples of solutions to the problem or similar problems. You will have pieces of the solution already available and useful to you, and you will have examples of failed attempts (just as important as the successes).

A product design effort is broadly about two things: creating new components and integrating existing ones. Every product is part of a system which includes the user and anything in the environment it has to interact with. This is the reason your hypotheticals fall flat: you are unable to include all the necessary information because you are not dealing with something real.

Many times, in the end, the successful product looks and acts very differently from what is first imagined. This can be mitigated to some extent by focusing properly during the process from conception to delivery on the level of abstraction required for each step.

I've mentioned elsewhere the 4D methodology a colleague and I developed for project lifecycle. The 4 D's are:

  • Discover (what is the problem, what is the environment it is in, and what are the constraints?)
  • Design (Given the information in the Discovery, what can we create that solves the problem?)
  • Develop (Given the Design, what technological and procedural creations will solve the problem in practice?)
  • Deploy (Given the developed system, how do we go about delivering it so it will actually succeed?)

So, your question starts in the middle of nowhere. The client is the expert in the problem to be solved. You are supposed to be the expert in characterizing that problem so a technological solution can be created. The list of things you started this with is like something jotted down in the Design phase in some random meeting. It is neither a requirement or a specification on its own.

STEP ONE in a successful product development is to understand what the product will do that makes it useful and valuable. "Storing a picture" or anything like that isn't that. Start with a high level description of what it will be like for the user to use the product to solve the problem. That "story" will drive everything below it. It is the best way to account for all the functional requirements. You start very high level and add details as you work out what is possible given the problem, the operating environment, and the constraints—then you start writing specifications.

For example, you might have a product that needs to communicate with the Internet. When you are describing the actual use of the product you might discover that the product needs WiFI, but also cellular connectivity based on that story of how the product will be used. You might also find, for example, the product must be able to be carried easily, and resist dropping and rain.

This is done in collaboration with the expert on the problem, that is, the customer who will buy it. Sometimes it might not be the people who contact you about it rather the people who work for them who really know how the process of their jobs work and what will make them easier or even doable.

One reason consultants have a bad reputation is because when approached about doing something like "can you make me a handheld device that can read barcodes and send them to our server" they say, "of course I can" and they do, only to have the client discover that it doesn't solve the problem which wasn't the device but what the device was supposed to do.

Suddenly, though the consultant was supposedly engaged to solve one problem (the handheld device), and did it perfectly, the client is very upset the problem they wanted solved isn't. A good consultant works with the client to discover the problem to be solved using the client proposed solution as a way into it. It could turn out the client has done excellent discovery and some design, and your job will be easy going forward. I have found that clients who have to look to the outside have not done so.

What you can expect in the real world from clients is a messy list of things from various phases and at various levels of abstraction. You will find some constraints to be entirely artificial and you have to lead the client away from these when they are incompatible with success within other constraints. You will find a lack of understanding by management of the workarounds used by the workers. You will find attempts to take a system based on manual operations and automate things that are completely unnecessary because of the automation.

In consumer products, you have to talk to the consumers. You have to look at what they can buy now, why they buy it, and how you can have a market for whatever you will make.

All of these things are needed long before a single technical requirement is. You have to understand the problem before you can hope to understand how to solve it.
 

Thread Starter

Pushkar1

Joined Apr 5, 2021
416
" My idea is to design and manufacture a product that will measure the Temperature and Humidity of my Green house, which is, located, approx. 50mtrs from my home.
.
Thank you very much @ericgibbs today i learned something new from you

Post what you consider, what is the next step?

The Green house unit will measure these parameters every minute and transmit by a radio link, using RS232 protocols, to a receiver in my house. The receiver will display and log the parameters to a SD card
E
Before proceeding further, I would like to clarify the questions arising in my mind. You want to measure the temperature and humidity data and display it on the receiver kept at your home. For this you want to use ras232 protocol.

can you tell why you chose only rs232 protocol, you may have other options like wifi?
 
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