Подрядная организация обновила график работ.

Because it agrees with организация, which is a feminine singular noun.

• подрядный = masculine
• подрядная = feminine
• подрядное = neuter

Since организация is feminine, the adjective must also be feminine:

• подрядная организация = contracting organization / contractor company

This is normal adjective-noun agreement in Russian.

That ending shows the verb is in the past tense feminine singular.

In Russian past tense, the verb agrees with the subject in gender and number:

• обновил = he updated
• обновила = she/it updated
• обновило = it updated (neuter)
• обновили = they updated

Here the subject is организация, which is grammatically feminine, so Russian uses обновила.

Because график is the direct object of обновила, so it is in the accusative case. But for inanimate masculine nouns, the accusative singular looks exactly like the nominative singular.

So:

• nominative: график
• accusative: график

That is why the form does not change.

Because Russian often expresses of-relationships using the genitive case.

So:

• график = schedule
• работ = of works / of tasks / of work activities

The basic pattern is:

• график чего? = schedule of what?
• график работ = work schedule / schedule of works

Here работ is the genitive plural form of работы.

In this phrase, работы usually means work activities, tasks, or construction works, depending on context.

So график работ is often best translated as:

• work schedule
• schedule of works
• project schedule

In business, engineering, or construction contexts, работы often refers to the actual work being carried out, not just a job in the employment sense.

It is a fairly formal expression meaning something like:

• contracting organization
• contractor company
• subcontracting organization (in some contexts)

A native speaker might also say подрядчик, which often means contractor more directly.

The difference is mostly stylistic and contextual:

• подрядчик = contractor
• подрядная организация = contractor organization / contracting company

The sentence sounds official or business-like because of подрядная организация.

Обновила is perfective.

That means the sentence presents the action as completed:

• обновила = updated / has updated

The imperfective partner is обновляла, which would suggest an ongoing, repeated, or process-focused action:

• Подрядная организация обновляла график работ. = The contractor was updating the work schedule / used to update the work schedule.

So in your sentence, the speaker is focusing on the fact that the schedule was updated as a completed result.

Because Russian has no articles.

Russian does not have separate words for:

• a / an
• the

Whether something is definite or indefinite is usually understood from context.

So Подрядная организация обновила график работ can mean:

• The contractor updated the work schedule
• A contractor updated a work schedule

In most real contexts, the surrounding situation makes it clear which meaning is intended.

Yes. Russian word order is more flexible than English because case endings show grammatical roles.

The neutral order here is:

• Подрядная организация обновила график работ.

But you could also say, for example:

• График работ обновила подрядная организация.

This puts more emphasis on график работ.

Or:

• Обновила график работ подрядная организация.

This can sound more marked or stylistic, depending on context.

So the original order is the most straightforward, but other orders are possible for emphasis.

You know from both case and verb agreement.

• организация is in the nominative case, which is the usual case for the subject.
• The verb обновила is feminine singular, matching организация.

Meanwhile:

• график is the object of the verb
• работ depends on график

So the structure is:

• Подрядная организация = subject
• обновила = verb
• график работ = object

The standard stresses are:

• подря́дная организа́ция обнови́ла гра́фик рабо́т

More specifically:

• подря́дная
• организа́ция
• обнови́ла
• гра́фик
• рабо́т

Stress is important in Russian, so this is worth learning early.

Yes, график can mean different things depending on context.

Common meanings include:

• schedule / timetable
• graph / chart

In график работ, it clearly means schedule, because работ tells you it is a schedule of work/tasks.

So here it is definitely not a mathematical or visual graph.

Sometimes yes, but the nuance is a little different.

• график работ often sounds like a planned schedule, especially in business, project, engineering, or construction contexts.
• расписание is more often used for a timetable or fixed schedule, such as classes, trains, or appointments.

So in this kind of formal/project context, график работ is the more natural choice.

Yes. It sounds very natural in formal, business, project-management, and construction contexts.

Words like:

• подрядная организация
• график работ
• обновила

fit well in administrative or professional language.

In more everyday speech, a speaker might choose simpler wording, but for official communication this sentence is very typical.