SlimeJCL — JCL → Spring Batch Transpiler
A SlimeNENC companion product. Carries COBOL-batch’s essential JCL counterpart through a bit-exact migration to Spring Batch / Workflow, leveraging maximum reuse of SlimeNENC IP.
Even if you bit-exactly transpile COBOL to Java with SlimeNENC, leaving JCL (job startup, I/O, scheduling) to the customer balloons the project from 6 months to 18 months, and SlimeNENC’s bit-exact claim collapses the moment the JCL side behaves differently. SlimeJCL closes that gap by bit-exactly migrating JCL into Spring Batch — achieving “migration project complete in one toolchain.”
SlimeJCL is an upsell-only product offered under the precondition of an active SlimeNENC license. It is technically and IP-wise designed around SlimeNENC integration, and we do not offer SlimeJCL as a standalone product. If you do not yet have a SlimeNENC license, please consider SlimeNENC first.
Key targets (Phase 4 GA goals)
(looser than SlimeNENC Subset A’s 99.9995% due to JCL syntax diversity)
IBM z/OS / Fujitsu FNJCL / Hitachi VOSJCL / NEC ACOS NCRP
Already in SlimeNENC corpus (CBSA + carddemo + Defects Suite + Portfolio + BankDemo)
Reuses SlimeNENC Subset A’s 9-stage architecture
One row in lex-prefix map + 5-10 attribute keywords (parser unchanged)
SlimeNENC’s S2-S5/S7-S8 stages reused for JCL
Relationship with SlimeNENC — Three-stage rocket
| Tier | Product | Precondition |
|---|---|---|
| 1 | SlimeNENC (Subset A: cross-language transpilation) | None — new customers OK |
| 2 | SlimeNENC + PSDP (Subset B: within-language parallelization) | SlimeNENC license |
| 3 | SlimeJCL (this product) | Active SlimeNENC license required |
land-and-expand:
[Year 1] Land with SlimeNENC — COBOL → Java migration [Year 1.5-2] Upsell SlimeJCL — JCL → Spring Batch, completing the COBOL+JCL pair [Year 2+] Apply PSDP — bit-exact parallelization shortens the nightly batch window ↓ Cloud-native (Spring Batch → AWS Step Functions / Airflow)
JCL Slot IR design — maximum reuse of SlimeNENC IP
Following SlimeNENC Subset A’s Slot IR (Core64 + Ext32) philosophy, JCL is normalized into a language-agnostic intermediate representation:
| JCL syntax | Slot ID | Description |
|---|---|---|
//<jobname> JOB ... | JCL-JOB | Job declaration (CLASS, MSGCLASS, TIME, NOTIFY, COND, etc.) |
//<step> EXEC PGM=<prog> | JCL-EXEC-PGM | Program execution step |
//<step> EXEC PROC=<proc> | JCL-EXEC-PROC | Procedure invocation |
//<dd> DD DSN=... | JCL-DD-DSN | Dataset reference (DISP/UNIT/VOL/SPACE/DCB) |
//<dd> DD SYSOUT=... | JCL-DD-SYSOUT | Spool output |
// JCLLIB ORDER=... | JCL-LIB | Procedure library reference |
// SET name=value | JCL-SET-VAR | Symbolic parameter setting |
// IF cond THEN / ENDIF | JCL-IF | Conditional execution (z/OS extension) |
Each Slot is Core48 + Ext16 = 64 bits, providing audit-chain compatibility with SlimeNENC.
9-stage pipeline (JS1-JS9)
SlimeNENC Subset A’s 9-stage architecture is reused for JCL; new implementation is limited to the emitter (JS6) and per-dialect lexer:
(integrated with SlimeNENC)
(DD shuffle, etc.)
Four major JCL dialect fingerprints
JCL dialect differences are concentrated in line-leading prefixes plus attribute keywords (no parser-wide variance like COBOL). Cost to add a new dialect: one row in the lex-prefix map + 5-10 attribute keywords (~30 minutes, parser unchanged).
| Dialect | Primary markers | Calibration state |
|---|---|---|
| IBM z/OS JCL | // <name> JOB ... (// + space), EXEC PGM=, EXEC PROC=, DD DSN=, DD SYSOUT=, JCLLIB ORDER=, &SYSUID, IEFBR14, SYSIN DD *, terminator /* /& | ✅ Most of the 233 existing files are IBM z/OS; bit-exact validation planned in Phase 4-3 |
| Fujitsu FNJCL (NetCOBOL) | /JOB (single slash, distinct from IBM’s //), /EXEC PGM=, /DD DSN=, /PROC, /AIM ... (Fujitsu transaction base) | △ Public-spec based, calibration via PoC in progress |
| Hitachi VOSJCL | \JOB (backslash), \EXEC PGM=, \FD file definition, KFSB*****-{E,I,W} message-ID convention, \TRN ... for OpenTP1 | △ Public-spec based, calibration via PoC in progress |
| NEC ACOS JCL (NCRP) | \$JOB or ;;JOB, \$EXEC PGM=, \$DD / \$FD, NCRP mentions | △ Public-spec based, calibration via PoC in progress |
Note: the prefix on the JOB line discriminates dialects with ~99% accuracy; the remaining 1% is settled by attribute patterns (CLASS/DISP keyword sets). Mirroring SlimeNENC’s 14-value dialect-detect, dialect-transpile coverage centers on IBM z/OS; Fujitsu/Hitachi/NEC are at the fingerprint stage with PoC-based conversion calibration in progress.
Spring Batch translation map (key entries)
| JCL syntax | Spring Batch equivalent |
|---|---|
// JOB CLASS=A,MSGCLASS=X,TIME=1440 | @Bean public Job <name>Job() + JobParameter("class", "A") + timeout config |
// EXEC PGM=COBOL_PGM | Step + Tasklet calling CobolPgm.main() (transpiled by SlimeNENC) |
// EXEC PROC=MYPROC | JobBuilder.flow().next(myProcSteps) |
// DD DSN=PROD.FILE,DISP=SHR | FlatFileItemReader + RandomAccessFile mode |
// DD DSN=PROD.OUT,DISP=(NEW,CATLG,DELETE) | FlatFileItemWriter + AfterJob listener |
// DD SYSOUT=* | Logback appender |
// DD * (instream) | String literal in @Bean |
COND=(8,LT) | JobExecutionDecider (evaluates prior-step exit code) |
// JCLLIB ORDER=PROD.PROCS | @Configuration class scan path |
// SET HLQ=AWS.M2 | @Value("${jcl.hlq:AWS.M2}") |
&SYSUID | System.getProperty("user.name") |
IEFBR14 (NULL prog) | () -> RepeatStatus.FINISHED (no-op tasklet) |
Existing validation corpus (no separate ingest required)
The validation JCL corpus for SlimeJCL is already in the SlimeNENC corpus — 233 files (bundled with COBOL repos cloned during Phase 1+2):
| IBM CBSA | 102 files (EPL 2.0, IBM’s official banking sample with CICS+DB2+BMS) |
|---|---|
| AWS carddemo | 55 files (Apache 2.0, official AWS Mainframe Modernization) |
| Defects Suite | 49 files (MIT, paired JCL for each .CBL) |
| Portfolio Mgmt | 15 files (sentientsergio, IBM z/OS extensions) |
| Rocket BankDemo | 12 files (Rocket EULA, internal QA only) |
| Total | 233 files, of which 221 are in the publicly distributable layer |
Typical use cases
| Financial batches | Migrate nightly core-banking batches bit-exactly with SlimeNENC (COBOL → Java) + SlimeJCL (JCL → Spring Batch) as a pair. Single-toolchain delivery cuts effort by ~50% while preserving an end-to-end audit-chain trail. |
|---|---|
| Cloud migration | For z/OS → AWS Mainframe Modernization / IBM Cloud / Azure migrations, converting the JCL side to Spring Batch makes the workload cloud-native and container-runnable. |
| Cron / Workflow migration | Spring Batch becomes the bridge to Apache Airflow / Argo Workflow / AWS Step Functions, enabling staged migration from SlimeJCL output. |
| Audit-grade batch consolidation | The full transformation chain (JCL → Spring Batch + COBOL → Java) is integrated into the SlimeNENC audit chain, allowing auditors to re-verify after the fact. |
Availability / Pricing
| Targeted GA | 2026-Q3 (after Phase 4-1 through 4-5 completion) |
|---|---|
| License model | Annual add-on attached to a SlimeNENC license (no standalone sale) |
| Indicative price | 30-50 % of the SlimeNENC base license fee (subject to market validation, finalized at GA) |
| Migration PoC | SlimeNENC + SlimeJCL paired PoC available as a separate professional service |
| Pre-orders | Pre-orders open in 2026-Q2 to existing SlimeNENC customers (priority allocation slots) |
Phase 4 roadmap
- Phase 4-1 (1 month)Implement JS1 JCL Lex (IBM z/OS), achieve 100% lex-pass on all 233 files, finalize Slot IR schema
- Phase 4-2 (2 months)JS6 Spring Batch emitter scaffold; convert 50 of 233 files to Spring Batch; measure javac PASS rate
- Phase 4-3 (3 months)Bit-exact comparison framework (JCL job execution vs Spring Batch execution); reach 99.95%+ on all 233 files
- Phase 4-4 (4-5 months)Add Fujitsu/Hitachi/NEC JCL dialect lexers (PoC calibration); audit-chain integration; Mini-PSV application
- Phase 4-5 (6 months)Public benchmark (CBSA + carddemo JCL converted via SlimeJCL with end-to-end behavior validation); productize for sales; GA
Related products
Pre-order (existing SlimeNENC customers) See SlimeNENC (Subset A) See PSDP (Subset B) See other products