Radni nalog ima servisni izveštaj.

It is both:

• grammatically, it is an adjective + noun phrase
• in real usage, it often works as a fixed technical term

So radni nalog is understood as work order, not just any random combination of working + order.

The same is true for servisni izveštaj: it is an adjective + noun phrase, but together it functions as the standard term service report.

The sentence follows the very common pattern:

subject + verb + object

So here:

• Radni nalog = subject
• ima = verb
• servisni izveštaj = direct object

That is very similar to English word order in a simple statement.

Ima is the 3rd person singular present tense of the verb imati, which means to have.

So:

• ja imam = I have
• ti imaš = you have
• on/ona/ono ima = he/she/it has

In this sentence, radni nalog is singular, so the verb is singular too: ima.

The main clue is the verb imati.

With imati, the thing that possesses something is the subject, and the thing possessed is the direct object.

So:

• Radni nalog = the thing that has something
• servisni izveštaj = the thing being had

Also, the default Serbian word order in a neutral sentence is usually subject + verb + object, so the first noun phrase is normally understood as the subject.

It is in the accusative, because it is the direct object of ima.

However, izveštaj is a masculine inanimate noun, and for masculine inanimate nouns in Serbian, the accusative singular is the same as the nominative singular.

So:

• nominative: servisni izveštaj
• accusative: servisni izveštaj

No visible change happens.

This is very common in Serbian. Compare:

• Vidim novi auto. = I see a new car.
  Here auto stays the same too.

If the noun were masculine animate, you would usually see a clearer change.

Because adjectives in Serbian must agree with the noun they describe in:

• gender
• number
• case

Both nalog and izveštaj are masculine singular, so the adjectives that go with them are also masculine singular:

• radni nalog
• servisni izveštaj

In this sentence, the object phrase still looks the same because, as mentioned above, masculine inanimate accusative often matches nominative.

Also, these are standard adjective forms you learn together with the nouns they modify.

Because Serbian does not have articles like English a/an/the.

That means Radni nalog ima servisni izveštaj could be interpreted in English as:

• The work order has a service report
• A work order has the service report
• The work order has the service report

Which English version is best depends on the context.

Serbian usually lets context show whether something is definite or indefinite.

Yes, Serbian word order is more flexible than English, but the neutral, most natural order here is:

Radni nalog ima servisni izveštaj.

If you change the order, you may add emphasis, contrast, or make the sentence sound marked.

For example, moving servisni izveštaj to the front could be possible in some context, but in this sentence it may also create confusion, because both noun phrases are masculine singular and look very similar in form.

So for a learner, the safest neutral order is the original one.

In Cyrillic, it is:

Радни налог има сервисни извештај.

Serbian regularly uses both scripts:

• Latin: Radni nalog ima servisni izveštaj.
• Cyrillic: Радни налог има сервисни извештај.

Because this sentence is using the Ekavian Serbian standard, where you get e in this word:

• izveštaj

In Ijekavian varieties, you often see:

• izvještaj

Both forms refer to the same word and the same meaning. Very broadly:

• izveštaj is typical in standard Serbian used in much of Serbia
• izvještaj is common in Bosnia and Herzegovina, Montenegro, Croatia, and some Serbian usage as well

So this spelling is a variety difference, not a difference in grammar or meaning.