OPS.11.1:4 - Solution

Construct the needed outside result, recover the work that obtains it, reconcile shared participants, and connect the quantities and events at each useful scale. Refine an account when its omitted distinction can change the proposed action. Return the resulting comparison with the conditions on which it depends.

OPS.11.1:4.1 - Fix the receiving result and the proposed change

State what the recipient must obtain and which event makes it available. For an order, this may require accepted components, transport and permission to use the result. For a machine service, it may be restored operation. Use the completion condition of the present service.

Name the alternative under consideration: another release time, a different allocation, a larger transfer batch, changed routing or another operating method. Identify the quantities that would make the alternative preferable and any conditions it must preserve. OPS.1 supplies the operating focus and OPS.19 the wider reconciliation when several results govern the choice.

Retain the difference between a fixed input and a decision variable. If a contractor’s two-day turnaround is a commitment that cannot change, the present model can use it as an input. If the proposal changes how that contractor is used, recover the response to that change rather than assuming the same turnaround.

OPS.11.1:4.2 - Recover what obtains the result

Follow one case from its relevant arrival to its receiving completion. At each step, identify the required input, what can happen next, the condition that enables it and what the step produces. Include external work when the result depends on it, even if that work is absent from the organization chart.

Separate the route from the resources used along it. For each consequential operation, determine which resources it holds and for how long. A machine may hold a part throughout a cycle while needing an operator only for loading and unloading. A person may be shared between apparently separate stations. A pool may provide alternatives only when the members have the needed capability and access.

Recover joins and returns. Two component outputs may both be needed before acceptance; a correction may revisit a resource already assigned to new work. A release rule must then account for unfinished obligations as well as newly admitted cases.

Represent the relevant network of transformations and conditions. Distinguish an input or result passed to another operation, a resource used by several operations, and a condition that enables an operation. Label those relations in a diagram or state them in a table. An arrow without a stated meaning can hide whether a result is needed, a person is occupied or someone must authorize the action. A route may branch, join or return; it need not be one predetermined sequence.

Connect that network to the commitments and authority on which it relies. Identify who can request, promise, declare completion and accept the relevant result. Those acts can themselves take time and consume resources. Their organizational meaning and their resource demand answer different questions. Counting a person’s existing assignments establishes demand on that person; it does not establish or redesign the person’s authority.

Compare an alternative by stating what changes: a transformation, its required inputs or outputs, an enabling rule, resource occupancy, a commitment or an authority relation. Keep unchanged relations available for reuse. A changed release limit or route does not by itself establish a change to the organization’s roles. Conversely, leaving the boxes and job titles unchanged does not establish that people can exercise a newly assigned responsibility.

A.22.CGUS helps express available continuations and their conditions before fixing a sequence. OPS.8 supplies readiness and release policy. Use the existing description of those relations when it already conveys them; the work does not require a particular diagram.

OPS.11.1:4.3 - Reconcile shared participants and operating conditions

Compare the local accounts at their connections. Establish whether two resource names denote the same resource, interchangeable members of a pool, or different resources. Do the same for cases, batches, deliveries and completion events.

Apply the constraint once to the actual shared participant. If one operator serves two stations, both demands compete for that person’s available intervals. If one vehicle carries several orders together, those orders share the trip; their inclusion does not create several vehicle trips.

Compare calendars and eligibility. Six hours of available labor and six hours of eligible work can remain incompatible when they occur at different times or require different skills. Conversely, an unattended stage can permit another operation during part of the same elapsed interval.

Keep different receiving questions distinct. The project sponsor’s completed result, the performer’s completed assignment and the administrator’s settled expense can have different boundaries. Connect the relevant events instead of treating the shared word “completed” as an identity. OPS.3 supplies subject recovery; F.0.1 and F.9 help when local meanings or their correspondence remain unresolved.

OPS.11.1:4.4 - Connect the quantities and events across scales

Choose the relationship needed between the accounts. Sometimes a wider quantity is a sum of disjoint local quantities. Sometimes it is a union, a maximum, a rate over an interval or a conditional response. Derive that operation from the receiving question.

For example, an order requiring every component becomes ready at the latest required component completion, provided no further work remains. Adding component completion times would describe neither that event nor the elapsed time. Parts processed together in a feasible machine batch share its occupation; take the union of that machine’s occupied intervals when calculating its busy time.

When aggregating, preserve the condition under which the summary is usable. A department’s average service rate may help a sustained-load question but leave the deadline of a particular batch unresolved. A sample-count summary may omit which order is waiting for its final sample.

To construct a sufficient summary, first express the requested result in the quantities you propose to retain. Derive the answer from those quantities and their stated conditions. If an omitted detail still enters the answer, look for two allowed arrangements with the same summary and different answers. Such a pair disproves sufficiency; failing to find one does not establish it. Retain the distinguishing relation, derive a useful bound, or restrict the answer. In the laboratory case below, the sample-to-order relation and the latest required completion provide the order’s completion event; sample totals alone cannot. C.29.1 develops this construction and preservation question. MMP.18 constructs compatible exchanges when mathematical models must be coupled, including shared quantities, time scales, feedback and uncertainty.

OPS.11.1:4.5 - Refine the part that can reverse the choice

Start from the smallest available account that addresses the question. Open a local part when a consequential result depends on its hidden timing, sharing, variation, return or completion condition.

A service block described by a fixed delay can be adequate for a question that leaves its load and resources unchanged. If the proposed release creates congestion inside that block, replace the fixed delay with the load-sensitive account needed for the comparison. Keep unaffected neighboring blocks at their sufficient level of detail.

Changing scope and changing detail are different moves. Adding a subcontractor widens the modeled operation. Showing the subcontractor’s internal batching adds detail. The first can be necessary while the second is irrelevant because the contract already supplies the required response.

Identify uncertainty separately from a deliberate simplification. “The loading time is unknown” calls for an estimate, range or observation if the answer depends on it. “We combine identical loading steps” is a modeling choice whose effect can be compared. C.11.DUA governs whether resolving an uncertainty is worth more than a restricted answer or a different action.

OPS.11.1:4.6 - Obtain and interpret the operating alternatives

Translate the recovered conditions into a form from which the requested result can be obtained. MMP.10 constructs constraints; OPS.10 selects the service and capacity question. Use a hand calculation when it suffices, or choose a computational procedure under C.29.2 and the relevant CMP methods.

Check the obtained alternative against the operating arrangement. Can the people and equipment occupy the proposed intervals? Are the receiving inputs available together? Does the calculated final event make the result usable? A schedule can satisfy a mistaken model, so successful computation alone does not settle these questions.

For a comparison across scales, return the local change and its wider consequence together. Explain where a delay, burden or unfinished obligation moves. OPS.14 supplies financial consequences when they can change the choice; their quantities need their own interpretation.

Stop with a sufficient comparison or the missing contribution that prevents one. Retain the assumptions a recipient needs to use the result. When routing, resources, calendars or acceptance changes, revise the affected account and propagate the change through the relationships that consumed it.