Flow of development

Flow of development ~ Development process of system and flow of process ~

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Development flow – System development process and process flow –

I would like to explain in a general example how to follow the flow (phase) in product development etc.
The development act requires a lot of resources. For details, please see before developing design.
The content to be described is a development process that can be used for both software and hardware.

First of all, why is there a trend in development activities is to “improve efficiency”. It is better to create the best one while keeping resources as low as possible. It is a common example to explain from now on. I think that there are also better ways depending on the contents that can be easily done without actually proceeding with such development, the size of development and the items to be developed. Please check it in each development.

Development overview

It is not necessary to go through the development process by taking steps in content developed at the individual level and development in a small scale / short term.
As I said, there is a development process as a way to keep the resources as low as possible while not mistaking the direction.

Even as a method of development, if there is no problem at all from the beginning of development to the completion of development, various things will not come out.
Although it is not limited to this, the following part comes out as you develop it, so you need the opportunity to consider the design itself.

· Unknown part if you do not try
· Parts that you do not know unless you test and evaluate
· Part that you do not know unless you actually use it
· Parts that can not be realized in principle after evaluation
· Part where customer ‘s request changed

Before the development process


PDCA cycle

The PDCA cycle is very important in improving it.
PDCA Loop PDCA Plan: Combine the plan, Do: Execute , Check: Evaluate and Act / Action: Feedback

It is one of the methods for smoothly advancing the administrative work, but it can also be used at the personal level.
I repeat the following 1 to 4, improve and improve and repeat spiral up.

By doing these, we can feed back the content that came up next, which is very useful for improvement and improvement.
It will become better by repeating the number of times.

1.Plan (plan / design)
2. Do (implementation and execution)
3.Check (inspection and evaluation)
4. Act / Action (treatment / improvement)

I will explain the flow of development, but it is no exaggeration to say that all parts of the loop are PDCA cycles.
This cycle can be used at any point in development and demonstrates its effectiveness in development.
Let’s make plans properly, execute, review and make improvements.

The PDCA cycle is not only for development, but also for a very important cycle to make it better

DR (design review)

Although I have said it several times, the development acts very much use resources (people, things, money, time). It will be very exhausted if you go forward in the wrong direction. For that, we need to stop once and see if the direction is right. We call it DR (design review).
We will work on collective intelligence to find out what we can not find in individuals or specific groups.

It is heavily used in the waterfall model development which is difficult to return to development.
However, in Agile development, we may also consider development direction by gathering non-members and developing members as a whole.
Let’s have the opportunity as much as possible because it will be an important point to confirm.

What is DR (Design Review)
Planning, development, design, manufacture, quality, purchasing collectively gather in the next step as to whether the criteria are met at the point of each development (before going to the next step of the development process) or the direction is wrong It is deciding whether to proceed.

The timing of the holding is mostly at the end of each development (before the next step), but there are places where the holding is skipped depending on importance.

Content to be determined by DR
Does the content that you did in that process fulfill the criteria at the point?
Is the remaining problem crushed as much as possible?
Direction and purpose are not wrong?

Especially the remaining task will be doubled if you postpone it, the next process will correct the problem.
Let’s proceed with completion of our process as much as possible.

Points to advance DR
I said the point to advance DR, but the points are the same at any meeting.
The meeting is very expensive as a company. (Because man-hours for the number of people is necessary for the meeting time)

There is also a thesis that the conference rate declines by 10% at every conference when there are more than seven at any conference.
The decision rate will also decrease, but the participants’ sense of responsibility will also fall.
It is abnormal that some people do not speak.
You have to speak some thought and find the best policy and compromise among them.

We also collect specialists from several departments.
Whether there is no problem in progressing development, we will reconfirm whether there is any problem in the relation item of the participating department in the point that it changed from before.

· Decide who is the decision-makers and responsible person and immediately make a decision during the meeting.
· Understand the contents in advance, give a problem in advance.
· It is necessary to keep as many as 10 people or less as possible (list the problems in advance materials).
· Collect multiple departments

Points above materials
Although data tends to be more frequent, it is necessary to keep a minimum amount of materials necessary.
It is impossible to understand even if it is too much, and it is the purpose of the material to convey information accurately.
Also, it is a place to judge whether to proceed next, so if you set it up with lie materials you may cause serious damage to the company.
Please note the neighborhood and make the material, please announce it.

· Do not lie to the contents of documents
· Presentation of concerns and problems that the speaker thinks

Issues Points in remarks / suggestions
People who make statements that take fried legs (people are good at taking a fault) inevitably tend to become inevitably, but as the first voice is positive as to make a constructive discussion in as short a time possible Let’s try something else.
For details, please read DESC talk .

DR is an important point.
The direction of decision and the way the company should go will differ if the attendees do not desire to have the necessity of holding itself.

DR (design review) stops once and really develops what you need development review point

It also describes the development process in detail.

Development method

I will explain three kinds of development process as a development method.
It can not be said that this is generally good, each has its own characteristics.

Recently, I stressed the testing process very much and I am in the direction to avoid rework as much as possible.
Therefore, it has been said that Agile type is better than Waterfall model.
However, development of V, W model incorporating the test process into the waterfall model is also frequently conducted.

· Waterfall model development (V-shaped model development) (W-shaped model development)

We divide top-down into work processes such as “request definition” “overview design” “detailed design” “development” “test and evaluation”.
In most cases there is no specific customer or customer interaction is only the first.
Waterfall Model_Request Definition _Overview Design_Details Design_Development_Test and Evaluation_etc

Since the flow of development through the stage is very easy to manage, it is a flow of development that has been used since a long time ago.
If there is no specification change in resources and duration, it will be estimated on a rough estimate.

· V character model development
V-shaped model development, W-shaped model development will be a variation of waterfall model development.
These are development processes, but strictly speaking, they are trying to incorporate the testing process to reduce backtracking.
I will explain that.

“Request definition” “overview design” “detailed design” “implementation” “test and evaluation” flow.
It is to carry out “test and evaluation” which makes pairing of “test and evaluation” here more concretely upper process.
It is called a V model or V character model because it seems that development process is going backwards, as we go through “test and evaluation” to move from small test to large flow as a flow.

As a flow of development here
“Request definition” → “overview design” → “detailed design” → “implementation” → “unit test” → “integration test” → “system test” → “acceptance test”
It will be like a shape. (Items change according to development)
Vモデル開発 流れとして小さなテストから大枠に移るように「テスト・評価」を行なっていく形が、開発プロセスの逆行しているように見える、VモデルまたはV字モデルと呼ばれます。

If this is sorted by the size of the range it will be V shaped as below.
In addition, as each test process is used to confirm the operation of consideration contents up to implementation, they are almost paired.
V If you divide the influence range of the 2 model items by size , In the part to be test progressed gradually going towards the larger range will be in the form of V

· W-shape model development
As I mentioned earlier, development of W-shaped model is a variation of waterfall model development.
Unlike the V type, the test process is further divided.

As a reason, even if there is an error in the examination contents prior to implementation and implementation in the V-shaped model, actual confirmation will be considerably later, so returning becomes very difficult.
It is a development / testing process that takes a lot of effort and takes the idea of ​​crushing them beforehand.

As an example of the flow of V-shaped model development up to the previous
“Request definition” → “overview design” → “detailed design” → “implementation” → “unit test” → “integration test” → “system test” → “acceptance test”

As an example of the flow of W-shaped model development
“Request definition” ⇆ “Request test” ➝ “Overview design” ⇆ “Design test” ➝ “Detailed design” ⇆ “Detailed test” ➝ “Single implementation” ⇆ “Unit test” ➝ “Integrated implementation” ⇆ “Integration test” → ” System integration “⇆” System test “→” Introduction “⇆” acceptance test ”
It will take the form of examination in the form like the examination content and implementation range. (Items change according to development)

Repeated parts circulate in the PDCA cycle and feed back.
We will increase the accuracy by that.

Like the V-shaped model, rearranging it by the size of the range will result in W shape as shown below.
In addition, as each test process is used to confirm the operation of consideration contents up to implementation, they are almost paired.
Sort by the size of the range as well as the V character model And it becomes W shape as follows.In addition, it is almost paired because it confirms the operation of consideration contents up to each implementation by each test process.


· Since the end of the process is clear, it is easy to manage the deliverables
· Management-friendly model from the management point of view
· Customer request and development functions are clear at the initial stage
· The product is completed according to the original requirements
· Since the experts are divided for each process, there is little difference in quality within the process


· If there is a mistake in each higher-level process, the problem gradually increases
· You tend to need more resources
· It is difficult to respond when customer’s request is changed
· Products can not be released until completion of development

A form that the product embodies from the design drawing at once

・Spiral model development

It is a model of the development process taking advantage of the top down design and the bottom up design.
It is a method to develop by repeating design and prototyping.
However, unlike Agile type, we will develop PDCA throughout the present while covering overall functions.
Communication with customers is often done closely so that they become gradually clear from the overview.
One loop period is relatively frequently about 6 months to 2 years.

As an example of the flow of spiral model development here
“Element design” → “Prototype design” → “Mass production prototype design” → “Mass production design”
It will be like a shape. I will cycle through each one. (Items change according to development)
In the development process that took advantage of the advantages of top-down design and bottom-up design It is a model that develops by repeatedly designing and prototyping


· Easy to predict program size and schedule.
· Easy to respond to customer’s request specification change.
· It is unlikely that the design process will increase and the time spent on mounting will be shortened.
· It is easier to manage on a relatively large scale than Agile model.


· Quality for functions tends to be ambiguous
· Products can not be released until completion of development

Form that gradually embodies products that were blurred

· Agile development

It is a generic name of a development method group that develops software so that it adapts quickly.
However, not only software but also hardware is quite effective.
We will try to minimize the risk by turning PDCA (design → test → survey → improvement) in a short term called iteration and dividing into functions and parts.
 The period of one iteration is relatively many times from one week to one month.

As an example of the flow of agile development here
“Function / Site” → “Function / Part” → “Function / Part” → “Function / Part”
It will be like a shape. I will cycle through each one. (Items change according to development)
Among them, interaction with customers is often done quite closely for each function / part.
When doing a combination, you must do a regression test (regression test: confirm a bug where usable functions can not be used).

Below is a flow of agile development while doing multiple simultaneous in parallel.
In the case of a single unit, it becomes one line in this figure.

In a short period called an iteration, divide it into small functions and parts PDCA ( We try to minimize the risk by turning design → test → investigation → improvement) The period of one iteration is relatively many times from one week to one month


· Reduce man-hours for returning trouble etc.
· Quality for product function can be preserved
· It tends to be customer’s request or street product
· Specification change to modification is quick to respond
· Can be released while limiting functions according to the delivery date


· Progress is difficult to understand and overall management is difficult
· Individuals are required to respond to changes in specifications
· Consciousness to maximize products including customers is required
· We can not cope unless communication is tightly taken
· If the test (test) method is lame, quality can not be maintained
· You must do a regression test for each combination
· It is often different from the original requirement specification
· Teams are divided for each function when the scale becomes large.
Therefore, since process experts are dispersed, the quality of each process tends to differ.

Form in which products gradually add functions and parts

Which one should be used in the development method?

It is not limited as explained below.
Because it is a development process after all, considering our company’s strengths, priorities, etc., it may be quite different from the contents described here.

· When you can restrict functionality from customer’s request
(Delivery time · Cost priority, but when it is required for quality to the introduced function)
→ Agile development

· When you can limit the delivery date / cost from customer’s request
(Introduction function priority, delivery time and cost tend to be different from the original estimate)
→ Spiral model development

· If you want to raise the company’s own technology and develop a new product
(If there are many resources, the development scale is large, if you want to manage well, there is no specific customer)
→ Waterfall model development (including V character and W shape model)

The development process will be an example of the flow of development after all.
Because each has their own features, let’s step on the development process so that we can make the most of the strengths of development method and company development method according to it.

The development process is an example of the flow of development after all. It is best to find out how to develop our strengths

This is also a reference for the development process.

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