| Course | AC550 Accounting Information Systems |
|---|---|
| Unit | Unit 4 |
| Paper type | Requirements analysis |
| Length | About 590 words, 5 pages double-spaced |
| Format | APA 7 student paper |
| School | Purdue University Global |
| Program | MS in Accounting |
| Updated | October 2026 |
Free sample paper for AC550 Unit 4
From 146 Angry Customers to 29 Testable Statements: A Unit 4 Requirements Analysis for Cylinder Rent Billing
[Student Name]
Purdue University Global
AC550: Accounting Information Systems
Unit 4 Requirements Analysis
[Instructor Name]
[Date]
Halvorsen Welding Supply, its dispute log and every figure are composite; the textbooks and guide cited are real.
Part 1: The Dispute Log
The billing clerk keeps a log of every rent dispute. Over six months it holds 146. Each was read and assigned to one primary cause.
1. Late keying of counter swap sheets: 58 disputes. Customers returned cylinders at the counter, but the swap was keyed a week or more later, after the rent bill ran.
2. Overwrites by the nightly transfer: 39. A manual correction was replaced the next night by the scan total.
3. Customer-owned cylinders billed as company cylinders: 21. The ownership flag was wrong or missing.
4. Wrong rent rate: 16. Contract rates were not updated after renewals.
5. Transfers between a customer's sites: 12. Cylinders moved from one ship-to site to another were counted at both.
The first two causes together explain 97 of the 146 disputes, two thirds. Both come from the way holdings are recorded, not from billing rules.
Part 2: Business Needs
From those causes, six needs follow, each a sentence about what Halvorsen must be able to know or do.
1. Know which serial numbers each account holds on any given day.
2. Record counter swaps by serial number at the time of the swap.
3. Keep a history of every change to an account's holdings, with who made it and why.
4. Distinguish company-owned from customer-owned cylinders in every holdings record.
5. Apply the contract rent rate in force on the billing date.
6. Track cylinders by ship-to site within an account.
Requirements written from the dispute log fix the causes of wrong bills, while requirements written from a vendor's feature list would only describe software, which is why the analysis states needs before any requirement.
Part 3: Requirements
The 29 requirements are grouped in four families and tiered. Tier 1 requirements are mandatory, tier 2 are strongly preferred and tier 3 are nice to have (Romney et al., 2021). Each is written so a vendor can answer yes, no or with configuration, uses "shall" for a single testable behavior, and cites the need it serves (Wiegers & Beatty, 2013). Examples from each family:
Holdings. H1, tier 1: The system shall store holdings as a list of serial numbers per account and ship-to site, with the count derived from the list. H4, tier 1: Every change to holdings shall record user, time, transaction type and prior value.
Capture. C2, tier 1: The counter application shall record each swap by scanning serials at the time of the transaction. C5, tier 2: Handheld voids shall require a reason code and remain in the audit log after sync.
Billing. B3, tier 1: Rent shall be computed from serial-level holdings on the billing date at the contract rate in effect. B6, tier 3: Customers shall be able to view their holdings online.
Control and reporting. R2, tier 1: The system shall produce a monthly list, by account, of serials held more than 180 days without movement. R7, tier 2: Integration with the general ledger shall post rent revenue by branch.
Traceability
A matrix links every requirement to one or more needs and every need to the causes in Part 1. Each need is served by at least one tier 1 requirement, and no requirement is orphaned (Hall, 2019).
References
Hall, J. A. (2019). Accounting information systems (10th ed.). Cengage.
Romney, M. B., Steinbart, P. J., Summers, S. L., & Wood, D. A. (2021). Accounting information systems (15th ed.). Pearson.
Wiegers, K., & Beatty, J. (2013). Software requirements (3rd ed.). Microsoft Press.
The Purdue Global AC550 Unit 4 instructions
Unit 4 of AC550 asks you to analyze a business problem and state system requirements. Start from evidence, such as a complaint log, interviews or error reports, and group it into causes with counts. State the business needs those causes imply, each as a sentence about what the organization must be able to know or do, before writing any requirement. Then write requirements as single, testable statements a vendor could answer yes, no or with configuration, grouped by family and ranked by priority tier. Include control and reporting requirements, not only functional ones. Build a traceability matrix linking requirements to needs and needs to causes, and confirm every need has a mandatory requirement. Avoid naming products. Support the method with accounting information systems texts and a recognized requirements source in APA 7.
How the AC 550 Unit 4 example is put together
Part one of the sample analyzes the dispute log: 58 disputes from late keying, 39 from overwrites, 21 from customer-owned cylinders billed as company cylinders, 16 from wrong rates and 12 from site transfers. Part two states six needs, from knowing serial-level holdings on any day to tracking cylinders by ship-to site. The highlighted sentence explains why needs come before requirements. Part three gives examples from four families: H1 storing holdings as serial lists, H4 logging every change with prior value, C2 scanning counter swaps, C5 requiring void reason codes, B3 billing rent from serial holdings at the contract rate, and R2 reporting idle cylinders. A traceability section confirms coverage.
AC550 Unit 4 rubric: what earns full points
Requirements analyses in AC550 earn points for evidence-based causes, clearly stated needs and requirements that can actually be tested. Graders check that causes are counted, that needs describe outcomes rather than features, and that each requirement states one behavior a vendor could confirm. The rubric rewards priority tiers, control and audit requirements alongside functional ones, and a traceability matrix showing that every need is covered. Analyses that start from a vendor's feature list, write vague requirements such as "user friendly," or omit control requirements lose credit. Linking the requirements back to the original complaint shows the analysis solves the actual problem. The requirements source and the systems texts belong in APA 7 references.
AC550 Unit 4 help: mistakes that cost points
Weak Unit 4 analyses jump straight to a list of features without analyzing the problem. Causes are asserted rather than counted from evidence. Needs and requirements are confused, so requirements read as goals. Requirements combine several behaviors in one sentence or use words that cannot be tested. Control requirements, such as change logs, are forgotten because they do not produce a bill. Product names creep in. There is no traceability, so the reader cannot tell whether every cause is addressed. If your section supplies interview notes instead of a log, a writer can group them into causes and derive needs and requirements from them.
Get an AC550 Unit 4 example written to your instructions
Whatever business problem drives the Unit 4 case, the custom analysis traces it to causes before it states requirements. Share the case, any complaint data or interview notes that come with it, and the rubric; the finished document arrives in 24-48h. The first custom sample is free and matches the format your instructor sets. The paper above is an original model document written by our desk, not a submitted student paper and not an official Purdue University Global document.
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AC550 Unit 4 questions, answered
What separates a business need from a requirement?
A need states an outcome the organization must achieve, such as billing rent only for cylinders a customer actually holds. A requirement states a specific capability a system must provide to reach that outcome, such as storing each cylinder movement as a dated event. Needs stay stable across products; requirements are what vendors answer, so the sample keeps the two in separate columns.
Why include control requirements in a systems analysis?
Because an accounting system is judged partly on whether its records can be relied on later, not only on whether it produces a bill today. Change logs, role limits and reconciliation of transfers belong in the requirements, since a package chosen without them may be impossible to fix afterward. The sample gives them a family of their own.
Can requirements come from interviews instead of a complaint log?
Yes, and many cases supply only interview notes. The method stays the same: group what people report into causes, state the needs those causes imply, then write requirements that answer the needs. Where evidence is thin, the sample's approach is to mark a cause as resting on one source, which lets a reader weigh it accordingly.
Where can I find a free AC550 Unit 4 sample paper?
This page holds a full AC550 Unit 4 requirements analysis for Halvorsen Welding Supply tracing 146 disputes to five causes, six needs and 29 tiered requirements with traceability and APA 7 references.
What makes a requirement testable?
It states one behavior with "shall" in terms a vendor can confirm or deny, such as storing holdings as a list of serials. Phrases like "easy to use" cannot be tested, so they are not requirements.