Class 8 Agenda Midterm Case Review Notes Transactions & Workflow Enterprise-level Applications –SCM – Supply chain mgmt –ERP – Enterprise resource planning –CRM - Customer relationship mgmt –EAI – Enterprise application Integration –“Coupling”: tight vs. loose –“Messaging” Text Chapter: Software in Flux

Transactions Definition: A single logical business event, that involves one OR MORE technical events, that should not be subdivided. Rules –Atomic –Consistent –Isolated –Durable

Transaction Management Issues Locality and timeliness of inputs –Dataflow issues from analysis –Data “held” until completion Multi-server transactions –2-phase commit Function separation –The “atom” in atomicity Large volume transaction issues –Commit points

Workflow Concepts Definition: The logical linking of transactions and business processes to accomplish a complex business event: “the assembly line” (e.g. Purchase Order)

Workflow Goals Process definition Instance Identification Process “stability” Invocation of “next step” Status availability Parallel processing Performance metrics

Workflow Issues: Multiple persons, servers, locations, applications Long durations Modularity of transactions –Interface points between steps –Messaging Pass the data Launch the process

Major Application Categories Suppliers Customers Processes SCM ERP CRM EAI

Enterprise Applications: Origins ERP systems Goal: manufacturing scheduling Functionality –Manage all inputs to ONE process –Firms have many ERP systems –Extensions for local processing common

Enterprise Systems: Strategies Infrastructure for applications –Common functions –Predefined, documented, supported –Development environment Hierarchical business rules, standards –Best practices –Customization options at several scopes Impact on “Fitgap” decisions –High risk, cost in modifications –Add-on functionality: a safe compromise

Modular ERP Systems HRS Core FMS Core Payroll Benefits Skills Accounting A / P Procurement

Peoplesoft-as-ERP-Example Notes HRMS vs FMS logic –Integration? –Common data? –Development environment? Layering of modules –Functional triangle –Rules, standards and defaults –Internal workflow management Integration –Security –Related applications –Reporting

Enterprise Application Integration Goals –Workflow between applications –Data consolidation between applications Scope issues –Tight / loose coupling –Enterprise –Channel Service-Oriented Architecture –The new model for EAI –Tune in next week!

Coupling Definition: How two processes share or pass information and services Options: –Tight: Linkage uses internal structures and logic so any change to one side impacts the other. Efficient but inflexible. –Loose: Linkage is based on external data only, so any changed process that produces the same “behavior” does not require a change to the other side. Less efficient but very flexible.

Loose Coupling Options Messaging Definition – for computers –Delivery of structured data to a process via a queuing mechanism Architecture –Queues Request/Response pairs –Manager –Clients

Messaging (2) Strengths –Asynchronous communication –Controls multi-server processes –Parallel processing –Reliability “Once and only once” delivery option “Publish and Subscribe” delivery Websphere MQ is most common –Evolved from mainframe “MQSeries” JMS (java messaging service) defines the standards for open systems

Messaging Server A Server B Message Queuing Server Q2Q1Q2Q3Q4 Queue Rules: Q1:… Q2:A-in Q2:B-out Q3: … Q4:B-in

Service Bus Next Week!

Chapter: Software in Flux A few points –Economies of scale and IS service providers  Enterprise smart decision  Portfolio management  SaaS precursor: ASP  Cloud computing precursor: Timesharing Discussion Questions What is impact on SDLC, other development principles? Strengths / weaknesses of SaaS model What new issues arise? Best fit vs integrated suite application models? Impact on IT departments?

Wednesday Service Oriented Architecture Case Study: Zara Final Exam structure Peer Production Questions –Time permitting Research Presentation prep-time