Lesson 15: コストを下げるために、ここの部品を変えました (Kosuto o Sageru Tame ni, Koko no Buhin o Kaemashita)

Explaining Reasons for Changes

English Title: Offering logical explanations for modifications

🎧 Audio:
Listen to this lesson

Role-play Setup

You are an engineer or product developer who has completed modifications to a design or prototype. Your superior wants to review the changes and understand what was modified and why. You need to report the completion of your work and explain the rationale behind each change clearly and concisely, showing how the modifications relate to business objectives like cost reduction.

Full Script & Explanation

Scene 1: Asking Permission to Report

Student:
今ちょっとお時間いいですか。
Ima chotto ojikan ii desu ka.
Do you have a moment?

Grammar Note: When beginning a conversation in the workplace, it’s important to ask if the person you would like to speak with has the time to talk. Rather than immediately diving into the 用件（ようけん）(main topic), use phrases like this to show the listener that you value their time. It is fine to omit「お時間」to make「今ちょっといいですか」. To be more polite, use「今（お時間）よろしいでしょうか」.

Superior:
ああ、いいですよ。
Aa, ii desu yo.
Sure.

Grammar Note: In this case, this phrase carries the same meaning as「はい、今、話しても大丈夫ですよ」. When speaking to a superior, use「はい、何でしょうか」or「はい、大丈夫です」.

Scene 2: Reporting Task Completion

Student:
あの、設計図の変更が終わりました。
Ano, sekkeizu no henkō ga owarimashita.
Well, I finished making the changes to the diagram.

Grammar Note: 「あの」is used to get the attention of the listener. This statement is made to let the superior know that the 作業（さぎょう）(work or task) has been finished. It is very important, especially when working on a team, to let others know what stage your work is at by making 報告（ほうこく）(reports).

Superior:
そうですか。じゃあ、ちょっと見せてください。
Sō desu ka. Jaa, chotto misete kudasai.
Oh, really. Could you just give me a look?

Grammar Note: In this case, although the speaker is using「ちょっと見せてください」, this may in fact mean that the speaker would prefer a 詳しい（くわしい）(detailed) explanation. When making reports, it is a good idea not just to show the final product, but to make an easy-to-understand 説明（せつめい）(explanation) of the process.

Scene 3: Being Asked About Changes

Superior:
前回のものと、どこが変わりましたか。
Zenkai no mono to, doko ga kawarimashita ka.
What’s new about this design?

Grammar Note: The speaker is asking the listener to explain the 変更点（へんこうてん）(changes). 「どこが」can be substituted for「なにが」in some cases. This phrase is likely to be used when 試作品（しさくひん）(prototypes) are being remade, or when meeting agendas or schedules have been changed.

🔑 KEY PHRASE

コストを下げるために、ここの部品を変えました。
Kosuto o sageru tame ni, koko no buhin o kaemashita.
I changed this part to reduce the cost.

Explanation:
This phrase is expressing two ideas: that the part was changed, and that this was done to reduce cost. In the fast-paced business world, phrases like this are useful to save time. 「ために」can be used to explain「原因」(causes) and「結果」(effects). This structure shows clear logical reasoning:

  1. States the objective (コストを下げる - reduce costs)
  2. Links it with ために (for the purpose of)
  3. Explains the action taken (部品を変えました - changed the part)

For example: 「部品を変えたために試作品は少し大きくなりました」(Since this part was changed, the prototype is a little bigger now.) In this case, since you are explaining something that has already happened, the past tense is used before「ために」.

Scene 4: Confirming Understanding

Superior:
なるほど。少し部品が大きくなったようですね。
Naruhodo. Sukoshi buhin ga ookiku natta yō desu ne.
I see. It looks like this part is a bit larger now.

Grammar Note: 「なるほど」is a phrase used to convey the idea that the explanation was understood. 「〜ようですね」(looks like, seems that) is used to show that a speaker’s perception of something has changed based on what has been seen or heard. In this case, the speaker is recalling previous versions of the design that they saw, or explanations that they previously heard.

Superior:
何か問題はありませんか。
Nanika mondai wa arimasen ka.
Are there any problems?

Grammar Note: The superior is checking if there are any issues with the changes that were made.

Student:
特にありません。
Toku ni arimasen.
Not particularly.

Grammar Note: When you believe there is no problem, be sure to directly say so. Rather than「ありません」, use「特にありません」to give a softer impression. If there is something that you are concerned about, use this phrase to ask for advice: 「問題ではないのですが、一つ気になることがあります」(There is no problem, but there is one part I am worried about.)

Scene 5: Moving Forward

Superior:
そうですか。じゃあこれで次の作業を始めてください。
Sō desu ka. Jaa kore de tsugi no sagyō o hajimete kudasai.
I see. In that case, please begin the next step.

Grammar Note: Since both parties agree that this part of the process is finished, the speaker is letting the listener know that it is okay to move on to the next step. In the workplace, it is vital to share the status of projects step-by-step when working. 「じゃあこれで」shows the shift to the next step.

Student:
わかりました。
Wakarimashita.
Understood.

Grammar Note: This phrase is being used to show acceptance of orders. If you are not sure what is being asked of you, then to clarify use phrases like「次に何をすればいいでしょうか」(What should I do next?) or「次の作業は～でいいでしょうか」(Should I do ~ next?).

Vocabulary

ちょっと - chotto - a little, a moment

「ちょっと」often has the same meaning as「少し」. However,「ちょっと」can also be used in a way that「少し」cannot. For instance, although you might be asked「ちょっと見せてください」(Could you just give me a look?), the person asking may actually want a detailed explanation. Similarly,「ちょっと時間ある？」(Do you have just a minute?) can actually end up being much more than just a minute. Depending on the situation and other factors, you must rely on context to know what the listener really wants. When you aren’t certain, make sure to ask.

Usage examples:

コスト - kosuto - cost

This word is borrowed from English, and is often used on the business scene. For businesses, it is always important to be mindful of reducing costs, because costs are directly connected to profits. Many Japanese phrases include the word “cost.”

Usage examples:

設計図 (せっけいず) - sekkeizu - design diagram, blueprint

Technical drawings used in engineering and manufacturing.

部品 (ぶひん) - buhin - parts, components

Individual components that make up a product or machine.

変更 (へんこう) - henkō - change, modification

Alterations made to plans, designs, or specifications.

Cultural Notes

The Importance of Reporting (報告 - Hōkoku)

In Japanese workplaces, regular reporting is essential for:

When reporting:

  1. Ask permission before beginning (今ちょっといいですか)
  2. State what task was completed
  3. Be prepared to explain the process and reasoning
  4. Clearly state if there are any problems

Explaining with ために (For the purpose of)

Japanese business communication values clear cause-and-effect relationships. Using「ために」shows logical thinking and helps others understand your decision-making process. This is especially important when:

Grammar Points

1. ～ために (tame ni) - For the purpose of, in order to

Used to express purpose or reason.

Formation: [Verb dictionary form] + ために
[Noun] の + ために

Examples:

Past tense usage: When explaining results of past actions, use past tense before ために:

2. ～ようですね (yō desu ne) - It seems/looks like

Used to express a judgment based on observation.

Formation: [Verb plain form] + ようですね
[い-adjective] + ようですね
[な-adjective] + な + ようですね

Examples:

3. 特に～ません (toku ni ~masen) - Not particularly

A softer way to give negative responses.

Examples:

Tips from this Dialogue

  1. Always ask permission before reporting - Use 「今ちょっといいですか」to show respect for the other person’s time

  2. Be prepared to explain your reasoning - Don’t just report what you did; be ready to explain why

  3. Use ために to show logical connections - This makes your explanations clear and professional

  4. Give definitive answers about problems - Use「特にありません」rather than vague responses

  5. Know when to move forward - When your superior says「これで」, it signals moving to the next step

Keigo (Polite Language)

Levels of formality for asking if someone has time:

Casual (to equals/subordinates):

Standard polite:

Very polite (to superiors/clients):

Kanji

変 (change, unusual)

Readings:

Compounds:

Practice Points

  1. Using ために to explain reasons and purposes
  2. Reporting task completion appropriately
  3. Asking permission before taking someone’s time
  4. Explaining changes with clear cause-and-effect
  5. Using 特に to soften negative responses

Source: NHK WORLD-JAPAN “Easy Japanese for Work” Lesson 15
https://www3.nhk.or.jp/nhkworld/en/tv/easyjapaneseforwork/skit15.html