CUCO case studies
CUCO · Put your knowledge to work in context.
CUCO is a multiple-choice certification exam in COBOL programming, aimed at developers who write, maintain, or modernize mainframe and COBOL-based business systems. It tests whether you can read and reason about COBOL source code rather than recall trivia: how the language's divisions fit together, how data is described and stored, how control flow executes, how files are processed, and how tables and subprograms behave. The exam is organized around seven weighted domains, with Fundamentals, Procedure Division, Data Division, and File Handling carrying the most weight, followed by Tables and Subprograms, Debugging and Testing, and Modern COBOL and Integration. Because questions are multiple choice, the discriminating skill is precise reading of code and data declarations, not memorization of syntax lists. The CUCO case studies are 5 cases and about 3,168 words.
1Packed-Decimal Amount Field Losing Its Sign in a Daily Settlement File
Northwind Mutual's nightly settlement job has run unchanged for six years. The input is a fixed-length file; the copybook describes AMT-DUE as PIC S9(7)V99 COMP-3, followed immediately by INVOICE-NO PIC X(10).
662 words, about 3 min2PERFORM THRU Fall-Through Prints a Summary Once per Customer
Atlas Freight's invoice-print program contains paragraph 200-PROCESS-CUSTOMER, which ends with no EXIT and is followed by 300-PRINT-SUMMARY and then 400-EXIT. The main routine uses PERFORM 200-PROCESS-CUSTOMER THRU 400-EXIT.
552 words, about 3 min3VSAM Alternate-Key Duplicate Status Stops the Promotion Extract
Ridgeline Retail's nightly promotion extract reads a VSAM KSDS customer file. The primary key is CUST-ID.
627 words, about 3 min4SEARCH ALL on a Table Loaded in Arrival Order Returns Wrong Reps
Bayline Insurance has a monthly commission program. It loads up to 200 sales reps into WS-REP-TABLE, which has OCCURS 200 TIMES ASCENDING KEY IS REP-ID INDEXED BY REP-IDX.
671 words, about 3 min5Decimal Point and Scaling Lost Between JSON Service and COMP-3 Amount
Orion Logistics exposes a COBOL batch module as a JSON service through an integration layer. The request contains an order amount as the JSON string "1234.50", a currency code, and an order date.
656 words, about 3 min