ACCTING2503 · Accounting Systems And Analytics
Transaction Processing, ERP Systems & System Documentation
This chapter is the Week 2 core of ACCTING 2503: how a raw transaction becomes decision-useful information, and how we draw the systems that do it. It covers the data processing cycle (input → storage → processing → output), how data is stored (general vs subsidiary ledgers, master vs transaction files, the audit trail) and coded, and how an ERP pulls every transaction cycle onto one integrated database. It then teaches the documentation techniques you must read, draw and tell apart — business process diagrams (BPMN), flowcharts (the physical model) and data flow diagrams (the logical model). The single most-tested idea here is the flowchart-vs-DFD distinction, a named sample-exam topic.
What this chapter covers
- 011. The data processing cycle — input → storage → processing (CRUD) → output, and what each stage decides
- 022. Data capture — the event/resource/agent facets, source-data automation and well-designed source documents
- 033. Data storage — general vs subsidiary ledgers, the storage hierarchy, and the audit trail
- 044. Master vs transaction files — permanent records vs period activity that updates them
- 055. Coding schemes — sequential, block, group and mnemonic (name and justify)
- 066. ERP systems — one integrated database across every cycle, with advantages mirrored by risks
- 077. Why we document — reading a system, evaluating internal control, and SOX §404 / ASA (ISA) 315
- 088. Documentation techniques — business process diagrams (BPMN), flowcharts (3 types) and DFDs (4 elements, 3 levels)
Worked example: critique a diagram and pick the right documentation tool
- +1A context diagram is the highest DFD level and must have exactly ONE process — showing two processes (1.0 and 2.0) is a level-0 diagram, not a context diagram.
- +1A context diagram has NO data stores — including the Inventory data store is an error (data stores first appear at level-0).
- +1A DFD of any level has NO decision diamonds — decisions belong to flowcharts, not data flow diagrams. The 'stock available?' diamond does not belong here.
- +1A DFD is a logical model (flow of data only); it should show data flows between the Customer entity and the process, not physical/decision logic.
- +1To evaluate internal control, use a document flowchart — it traces the flow of documents between people and areas and shows decision points, which is exactly where control strengths and weaknesses appear.
- +1Justify the choice: a flowchart is a physical model that captures who handles each document and where authorisation/segregation happens; a DFD deliberately hides that detail, so it is the wrong tool for a control review.
Key terms
- Data processing cycle
- The four-stage loop that turns raw data into information: data input (capture) → data storage → data processing (CRUD: create, read, update, delete) → information output. It also governs what is stored, who may access it, and how data is retrieved and reported.
- Source-data automation
- Capturing data in machine-readable form at the point of the activity — ATMs, point-of-sale scanners, RFID — so it enters the system with fewer keying errors. Paired with well-designed source documents (pre-numbering, prompts, mandatory fields) to raise accuracy and completeness.
- Master file vs transaction file
- A master file holds permanent records (the customer or inventory master); a transaction file holds a period's activity (this week's sales). The transaction file updates the master file — never the reverse. Reversing this direction is a classic exam error.
- Audit trail
- The traceable path of a transaction from source document through journal and ledger to the financial reports — and back again. It lets an auditor trace a reported figure back to its source (completeness) or vouch a source document forward to the report (occurrence).
- Coding schemes
- Systems for numbering data so it sorts, subtotals and validates efficiently: sequential (consecutive pre-numbering, catches gaps), block (ranges reserved to categories), group (positional sub-fields that each carry meaning — the chart of accounts) and mnemonic (letters/digits that hint at the item).
- ERP (Enterprise Resource Planning)
- A system that integrates all of an organisation's data into one overall AIS, so finance, HR/payroll, order-to-cash, purchase-to-pay, manufacturing and CRM share one integrated database. Its strength (a single source of truth, no re-keying) is also its risk (cost, complexity, single point of failure).
- Data flow diagram (DFD)
- A logical model showing only the flow of data through a system, using four elements — data source/destination (entity), data flow, process (transformation) and data store. It has no decision diamonds and no physical media, and decomposes in levels: context (one process, no data stores) → level-0 → level-1.
- Flowchart
- A physical model that shows media, devices, manual vs automated steps and — uniquely — decision points. Three types: document (best for analysing internal control), system (input → process → output, for systems analysis/design) and program (a single program's logic).
Transaction Processing, ERP Systems & System Documentation FAQ
What is the difference between a flowchart and a DFD?
A flowchart is a physical model — it shows how and where processing happens: the documents, devices, whether steps are manual or automated, and the decision points (diamonds). A DFD is a logical model — it shows only what data flows between entities, processes and data stores, with no decisions and no physical media. The quick tells: diamonds and devices mean flowchart, never a DFD; and a DFD's job is to strip a system back to pure data flow.
What are the rules for a context diagram?
A context diagram is the highest level of a DFD and must have exactly one process and no data stores — it shows only the external entities and the data flows in and out of the single system bubble. The two errors that lose easy marks are drawing more than one process (that is a level-0 diagram) or including a data store (data stores first appear at level-0). From there, level-0 explodes the single process into numbered processes (1.0, 2.0…) and level-1 explodes one of those into sub-processes (1.1, 1.2…).
Why is documentation examinable at all — isn't it just drawing pictures?
You study it for three reasons: you must be able to read an existing system, you must evaluate its internal control from the diagram, and the law requires it. Sarbanes-Oxley §404 requires management to document and assess internal control and auditors to test it, and under ASA 315 / ISA 315 the auditor must understand the entity's information system and internal control — which means reading and evaluating exactly this documentation. So flowcharts and DFDs are a control and compliance skill, not decoration.
What are the advantages and disadvantages of moving to an ERP?
Advantages: data is captured once and visible to every module (no re-keying), integration gives a single version of the truth, real-time cross-functional reporting, stronger access controls and embedded best-practice workflows. Disadvantages: high cost and long, disruptive implementation time; complexity and user resistance; and a single point of failure plus over-standardisation (you may have to bend your processes to fit the software). The exam wants both sides — the same feature, one shared database, is both the headline benefit and the headline risk.
How is this chapter assessed in ACCTING 2503?
Week 2 material sits on Test 1 (fast, case-based questions — naming coding schemes, classifying files, picking the right documentation tool) and recurs in the closed-book final exam (six compulsory case-study questions worth 50%), where 'flowcharts vs DFDs vs program flowcharts' is a named sample-exam topic. Power BI is excluded from the final, but everything in this chapter is fair game — so treat documentation and ERP as core, not optional.
How do I tell a master file from a transaction file in a scenario?
Ask which record is permanent and which is periodic. The master file is the standing reference — the customer master, the inventory master — that persists across periods. The transaction file records the activity for a period (receipts, sales) and is used to update the master's balances. The direction is fixed: the transaction file updates the master file. If a scenario says the master file updates the transaction file, that is the trap.
Exam move
Lock down the four-stage data processing cycle first (input → storage → processing → output) because every other topic hangs off it, then drill the clean distinctions the case questions reward: master vs transaction file (the transaction file updates the master), the four coding schemes (always name and justify), and — above all — flowchart vs DFD. Practise the flowchart-vs-DFD move until it is automatic: DFD is logical with four elements and no diamonds, a context diagram has exactly one process and zero data stores, and a document flowchart is the tool for evaluating internal control. For ERP questions, never list advantages alone — pair each advantage with its mirror-image risk and finish with a reasoned recommendation and mitigation. Finally, be ready to justify why we document at all (read the system, evaluate control, and satisfy SOX §404 / ASA 315), since a short 'why' often carries marks in the final.
