**Alternate Sequencing Opportunities (Removing Preferential, Soft Logic to Look for Sequence Optimizations)**

**Challenge:**

Construction projects are inherently complex, with countless ways to approach the build. However, most project teams face the challenge of limited time and resources, making it impossible to evaluate all viable alternatives. Typically, they assess one or two construction scenarios, and with the expertise of senior planners, select the “best” option to move forward. Legacy technology makes it really difficult to truly explore and find the best way to build.

**Solution:**

In this article, you will learn how to explore alternative sequences in ALICE by relaxing the logic constraints in your schedule. Imagine this: if we keep all the logic in your schedule unchanged, you are telling ALICE that every activity must follow the same rigid path, leaving no room for variability or alternatives. To uncover new possibilities, we need to show ALICE where flexibility exists.

Is the variability in the trade logic you have incorporated? Or perhaps in the number of resources assumed? Maybe it’s in the movement of resources within the project footprint (e.g., from zone A to zone B)?

With ALICE, you can quickly resequence to test different ideas and find the optimal solution. ALICE respects all preferential logic constraints you input, giving you the power to tightly control the sequence or remove all but the most essential logic ties to explore new sequences.

Remember, ALICE can only work with the data you provide. It will schedule based on the constraints you input. Leverage the flexibility and let ALICE help you find the best path forward.

Here is a refresher on the difference between hard logic and soft logic (preferential logic).

**Visual Example:**

Let’s dive into how sequence exploration works in ALICE with a visual example:

#### Fixed Sequence:

Consider a schedule where all relationship logic in the activity is fixed. There is only one sequence option on this end of the spectrum: A → B → C. This represents the schedule you provide upon import to ALICE or create from scratch with all logic constrained.

#### Free Sequence:

On the other end of the spectrum, removing all preferential logic allows ALICE to consider every possible combination. In this case, six sequences are possible:

A → B → C

A → C → B

B → A → C

B → C → A

C → A → B

C → B → A

However, is full sequence exploration realistic? For linear horizontal projects like bridges or roadways, breaking logic between adjacent sections may not be feasible.

#### Optimized Sequence:

The recommended approach for sequence optimization in ALICE is to selectively remove preferential logic. This allows ALICE to explore a realistic range of sequencing options, finding the optimal path forward.

## How to Impact the Bottom Line:

With ALICE’s data-driven insights, you can make informed decisions by selecting the best path to construction. Cost/benefit analysis can be conducted to find the least costly and least risky plan.

**How ALICE is Different from Other Tools:**

Traditional CPM (Critical Path Method) scheduling is inherently fragile. All logic is linked as “hard logic,” meaning that when a risk event occurs, the schedule often “breaks.” This leads to the schedule's end date and key milestones being pushed back. Schedulers try to mitigate this by adding contingency or float to make the schedule more resilient to delays. However, this resilience only goes so far before fragility sets in again.

ALICE offers a solution to this problem. By removing select preferential logic, ALICE allows for the exploration of alternative sequences while ensuring all constraints are satisfied. This approach makes the schedule antifragile, or agile, enabling it to adapt and thrive under changing conditions.

**Example Use Case:**

I am managing the construction of a new road expansion as an *Infrastructure Contractor*. The project involves several key phases:

- Roads
- Structures: broken out into Phase 1 and Phase 2

The schedule is quite linear, with each phase starting only after the previous one is fully completed.

*Roads → FS → Structures*

However, within the Structures phase, I decided to start “Civil Works and Site Prep” at Phase 1 location first, then proceed at Phase 2 location.

*Structures: Civil Works and Site Prep Phase 1 → FS → Structures: Civil Works and Site Prep Phase 2*

This decision was arbitrary. This initial schedule gives me a total duration of 1,312 days.

I decided to remove only this soft logic in my schedule to see if ALICE would find a more optimal schedule.

I ran a new scenario in ALICE using the same constraints as before. The only change is the removal of one soft logic tie. The overall project duration was reduced from 1,312 days to 1,288 days, saving 24 days overall.

Reviewing the Gantt overlay comparison schedule, I can see that ALICE decided that completing Phase 2 location first produced a more optimal overall result than my original assumption.

And this is just one simple example of the power of resequencing and optimizing in ALICE.

**How to Optimize Sequencing in ALICE:**

##
**Step 1:**

Evaluate where the preferential logic exists in your schedule.

##
**Step 2:**

Remove the preferential logic one by one, or in bulk.

*Tip: On the Plan page, export the .csv to save a copy of your original plan before changes (before removing preferential logic). If you want to explore a different resequencing strategy, you can quickly go back to the original plan by reimporting the .csv. *

**Step 3:**

Run a new scenario to evaluate the result. Does the new schedule provide a more optimal solution to meet your project objectives? If not, try a different strategy.

**Step 4:**

Repeat steps 2 and 3 to try different strategies. For each sequencing strategy, you can also run different scenarios with different constraints, such as different resource availability, calendar assignments, production rates, milestones, etc.

##
**Step 5:**

Select the best optimization sequence and export the schedule to your desired format.